Dissertations / Theses: 'Stereophotogrammetry'

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Murphy, Norman. "Ankle and subtalar joint kinematic description using stereophotogrammetry." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61674.

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Henry, Robert Stuart. "Artefact detection and measurement of surface change in stereophotogrammetry Data." Thesis, Ulster University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646848.

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The diagnosis and treatment planning of disease may require image data acquisition using a range of 3D medical imaging modalities. These modalities include computed tomography, magnetic resonance, single photon emission computed tomography and positron-emission tomography. In combining images from such modalities, clinicians are provided with aligned data sets that have structural and functional information from within the body. However, no external textural data of the body surface (skin, wounds, and surface disease) is collected. Stereophotogrammetry can produce high resolution topographical surfaces with texture information and is becoming more readily available in the clinical environment. Combining stereophotogrammetry surface data with conventional 3D medical imaging data has the potential to allow improved visualisation of the 3D image data and to provide information on how surface data relates to the patient's internal anatomy. Medical image data is prone to outliers and artefacts due to physical limitations of the modalities involved and patient specific characteristics. To combine a variety of image data into a universal co-ordinate frame an image registration method is required. Outlier-robust registration is required due to the presence of artefacts and noise within the surfaces and images. A range of registration methods are evaluated using phantom test objects in the presence of outliers, simulated as noise, to determine the performance of the registration algorithms. A novel automated method is proposed to identify and examine artefacts at the surface edge of stereophotogrammetry data, using previously acquired registered volumetric image data as a reference. The largest stereophotogrammetry artefacts are observed at the surface edge and have a negative impact on the registration accuracy. Identification and removal of these surface edge artefacts is investigated using novel automated cleansing algorithms. The proposed cleansing methods are evaluated using quantitative and qualitative measures to assess the level of success for the implemented approaches. Results are presented in which stereophotogrammetry surface accuracy can be increased whilst ensuring that the surface is suitable for visualisation. Surface change can potentially indicate underlying anatomical change due to patient growth or disease. An automated algorithm is proposed to identify and measure regions of surface change in phantom stereophotogrammetry surfaces. These surface change regions are identified using information obtained from the registration of the stereophotogrammetry surfaces and the corresponding volumetric image. The preliminary results indicate that the proposed method can be used to locate and measure regions of surface change over time in stereophotogrammetry data.

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Henseler, Helga. "Three-dimensional breast assessment by multiple stereophotogrammetry after breast reconstruction with latissimus dorsi flap." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2981/.

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Introduction: Numerous methods exist for the assessment of the female breast. Traditionally, a subjective approach was taken for surgical planning and evaluation of the postoperative outcome. Several objective methods have been developed to support this procedure, among which are laser scanning, MRI, mammography, ultrasound and photography. Recently, 3D imaging technology has been developed. Material & Method: 3D breast assessment by multiple stereophotogrammetry was examined. A custom-made imaging system with eight digital cameras arranged in four camera pods was utilised. This system was used for breast capture, resulting in eight images obtained by the cameras. The merging of these images and 3D image construction was carried out by C3D software and the volume assessment of the 3D images was made using breast analysis tool (BAT) software, developed by Glasgow University. A validation study was conducted. Nine plaster models were investigated and their volume determined by 3D stereophotogrammetry and water displacement method. Water displacement was considered to be the gold standard for comparison. The plaster models were specially made in order to represent a variety of shapes and sizes of the female breast. Each plaster model was examined 10 times by each method. Further, the volumes of the breasts of six female volunteer live models were investigated by the same two methods and the results compared. A special focus was placed on the reproducibility of the assessment. Each live model was captured with the 3D capture system three times at two different time points after retaking a special pose in a custom-made positioning frame. Altogether, each live model was captured six times, resulting in six 3D images, each of which was measured three times with BAT software. A patient study was conducted in 44 patients after unilateral immediate breast reconstruction with Latissimus dorsi flap and no contra-lateral surgery. Each patient underwent 3D imaging with the multiple stereophotogrammetry system. During capture, the special pose in the custom-made positioning frame was taken by the patient’s leaning forward almost horizontally with the upper body for the breasts to rise off the chest wall to enable full breast coverage by the cameras. 3D images were constructed with C3D software and volumes measured with BAT. For each patient, one 3D image was constructed and measured four times with BAT software. In addition to the volume determination, a shape analysis was conducted. For this purpose, 10 landmarks were determined according to recommendations in the literature. Two landmarks, sternal notch and xiphoid, were marked, forming an imaginary midline between each other and four landmarks on each breast, i.e. the medial and lateral ends of the infra-mammary fold, and the most prominent and most inferior breast points were utilised for symmetry assessment between the right and left breasts. Each landmark was recorded four times by the operator on the 3D image and three-dimensional coordinates obtained. By assessment of the left and right breasts a breast asymmetry score was calculated. Firstly, breast asymmetry was assessed objectively on the 3D images through the centroid size, which was determined as the square root of the sum of squared Euclidian distances from each landmark to the centroid. The centroid was the geometric mean of the landmarks. Secondly, asymmetry was assessed through breast volume by application of BAT software. Thirdly, asymmetry was examined through the landmarks themselves by investigation of the mismatch of the landmark configuration of one breast and its relabelled and matched reflection. The non-operated and reconstructed sides were compared and landmarks were recorded by the operator in three dimensions in four repeated tests. A decomposition of the total landmark asymmetry into its factors was conducted by fixation of the surface of the non-operated side and translation, rotation and scaling of the surface of the reconstructed side. For comparison, a subjective breast assessment was conducted by six expert observers who rated the results after breast reconstruction by subjective qualitative assessment of the symmetry in 2D images of the same 44 patients in six poses. For this purpose the Harris scale was utilised, providing a score of 1 to 4 for poor to excellent symmetry. Results: The results revealed that differences in the obtained volumes in the plaster models were not significant. In contrast, differences in the breast volumes measured in the live models were significant. The examination of the reproducibility revealed that overall reproducibility obtained by stereophotogrammetry was better than that obtained by water displacement. No correlation between breast size and reproducibility of the measurements was found. The results of the patient study demonstrated that the reproducibility of the landmarks was within 5 mm. There was a non-significant difference of the centroid sizes between both breasts. There was a significant difference of the volumes between the two breasts, with the non-operated side being larger than the reconstructed side. Volume was considered to be a more accurate measure for comparison of both breasts than centroid size as it was based on thousands of data points for the calculation as opposed to only four points of the centroid size. The statistical analysis of the landmark data provided a mathematical formula for determination of the breast asymmetry score. The average asymmetry score, derived by landmark assessment as the degree of mismatch between both sides, was 0.052 with scores ranging from 0.019 (lowest score) to 0.136 (highest score). The decomposition of the landmark-based asymmetry revealed that location was the most important factor contributing to breast asymmetry, ahead of intrinsic breast asymmetry, orientation and scale. When investigating the subjective assessment, the inter-observer agreement was good or substantial. There was moderate agreement on the controls and fair to substantial intra-observer agreement. When comparing the objective and subjective assessments, it was found that the relationship between the two scores was highly significant. Conclusion: We concluded that 3D breast assessment by multiple stereophotogrammetry was reliable for a comparative analysis and provided objective data to breast volume, shape and symmetry. A breast asymmetry score was developed, enabling an objective measurement of breast asymmetry after breast reconstruction. 3D breast assessment served as an objective method for comparison to subjective breast assessment.

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Junior, Alvaro Augusto Junqueira. "Análise antropométrica facial de um grupo de adultos jovens brasileiros saudáveis por meio da técnica da estereofotogrametria: estudo piloto." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/58/58133/tde-07022014-135551/.

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A face humana apresenta características próprias de acordo com a oclusão dentária, harmonia facial, musculatura orofacial, além do formato e configuração das estruturas craniofaciais. Tradicionalmente, medidas antropométricas têm sido adquiridas através de medições diretas de um sujeito em ambiente clínico, utilizando-se de compassos e fita métrica para medir distâncias ou arcos entre pontos de referência. Com o avanço científico e tecnológico, os dados anteriormente analógicos passaram então a ser digitais. Isto abriu a possibilidade de aquisição rápida, precisa e sem radiação, com suas informações sendo simultaneamente arquivadas para análises futuras e podendo ser compartilhadas facilmente com pacientes e colegas. Dentre as novas modalidades de análise facial a técnica da estereofotogrametria tem se destacado, onde um grupo de câmeras de captura rápida fotografam o sujeito a partir de múltiplos ângulos. O objetivo desse trabalho foi analisar o perfil facial de um grupo de jovens adultos brasileiros assintomáticos para Disfunções Temporomandibulares (DTMs), com idade entre 18 e 30 anos através da técnica da estereofotogrametria, definindo características faciais comuns a este grupo, criar um banco de dados de mensurações faciais de uma parcela da população brasileira adulta jovem saudável para uso em futuros estudos complementares e testar a precisão e repetibilidade do aparelho Vectra M3®. Participaram do estudo 60 brasileiros adultos jovens sem DTM, sendo 30 homens (GH) e 30 mulheres (GM). O diagnóstico da DTM foi realizado com o Research Diagnostic Criteria For Temporomandibular Disorders (RDC/TMD). Após avaliação Odontológica inicial, foram realizadas marcações craniométricas transitórias em tecido mole e estes sujeitos foram submetidos à aquisição de imagens pela técnica da estereofotogrametria. Trinta e um pontos de referência (landmarks) foram utilizadas para realizar as medidas (em mm) de 42 distâncias. A repetibilidade do aparelho foi testada em 20% da amostra (12 sujeitos), não havendo diferença estatisticamente significante (p>0,05) em nenhuma das 42 distâncias entre a primeira e a segunda aquisição. Os resultados obtidos possibilitaram a criação de um banco de dados de mensurações faciais de uma parcela população brasileira jovem saudável. As distâncias Tr-N, N-Sn, Tr-G, Ls-Sto, Sto-Li, En[r]-En[l] e Prn-Sn não mostraram-se estatisticamente diferentes entre os grupos GH e GM, sendo que as outras 35 medidas apresentaram-se significantemente maiores no grupo GH. O aparelho de estereofotogrametria Vectra M3® mostrou alto grau de precisão e repetibilidade. The human face presents characteristics according to dental occlusion, facial harmony, orofacial musculature, besides the format and configuration of craniofacial structures. Traditionally, anthropometric measurements have been acquired through direct measurements of a subject inside clinical environment, using calipers and metric tapes to measure distance between arches and landmarks. Along with scientific breakthrough, the data, used to be analogic, became digital. It opened the possibility of quick, precise and radiation-free acquisitions, with its details being simultaneously archived for future analysis and being able to be easily shared with patients and colleagues. Among new facial analysis methods the stereophotogrammetry technique has emerged, where a group of cameras with fast acquisition take photographs of the subject from multiple angles. The aim of this work was analyze the anthropometric profile of a group consisted of young Brazilian adults without symptoms of Temporomandibular Disorders (TMDs), aged between 18 and 30 years old, defining facial characteristics that are common to them, create a database of facial measurements for a portion of a young healthy Brazilian population to be used in future works and test the precision and repeatability of the Vectra M3® equipment. 60 young adult Brazilians without TMD participated in this study, 30 males and 30 females. The TMD diagnose was accomplished with the Research Diagnostic Criteria For Temporomandibular Disorders (RDC/TMD). After early Odontological exam, temporary craniometrical landmarks were performed in soft tissue and those subjects underwent to imaging acquisition by the stereophotogrammetry technique. 31 landmarks were used to make the measurements (in mm) of 42 distances. The equipment repeatability was tested in 20% of the sample (12 subjects), not having statistically significant difference (p>0.05) in none of the 42 distances between first and second acquisitions. The obtained results allowed the creation of a database containing facial distances of a portion of a young healthy Brazilian population. The distances Tr-N, N-Sn, Tr-G, Ls-Sto, Sto-Li, En[r]-En[l] e Prn-Sn didn\'t show statistical difference between the group GH and GM, while the other 35 distances were significantly greater in GH. The equipment Vectra M3® showed a high level of precision and repeatability.

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Cousins, Michael. "An investigation into the use of stereophotogrammetry for the analysis of craniofacial dysmorphology in schizophrenia." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/15467.

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Studies of craniofacial dysmorphology in schizophrenia, carried out since the 1960s, have reported minor physical anomalies in those with schizophrenia, prominently in the craniofacial region. Indirect methods, most notably 3D laser imaging, have been used previously for investigating craniofacial dysmorphology in schizophrenia. This project aimed to investigate the ability of a stereophotogrammetry system to detect craniofacial dysmorphology in individuals diagnosed with schizophrenia. Furthermore, observed dysmorphology was characterised and compared with that found in previous studies. Three-dimensional craniofacial landmark coordinates were obtained from images collected using a bespoke design stereophotogrammetry system. The system includes a camera rig and a calibration rig. On the camera rig is mounted three digital single-lens reflex cameras hardwired to a trigger for simultaneous image capture. The calibration rig consists of a frame with strategically positioned retro-reflective calibration markers of known 3D orientation. The precision and reliability of the stereophotogrammetry system was tested using a human subject. Measurements were taken using the system and directly using callipers by two operators on two separate occasions. Intra- and inter-operator precision and inter-modality reliability were calculated and scored. All intra- and inter-operator precision scores were at least below a 7% error, and considered "good". Inter -modality reliability scores had at least a "good" score in 72% of all measurements. Excluding one soft landmark and one landmark with small measurement value, all inter-modality reliability scores were at least "good". The study cohort consisted of 17 African (8 control, 9 schizophrenia) and 13 Caucasian ( 8 control, 5 schizophrenia) males. A set of 18 landmarks focused about the eyes, nose, mouth and chin was identified for each subject and collated in 3D coordinate space. Geometric morphometric analysis - particularly generalised Procrustes analysis and principal component analysis - was carried out on these landmark sets. Discriminant Function Analysis was applied to identify discriminating features in the data set, and classification techniques, aided by feature selection, were applied to separate affected and control subjects. In the African cohort, the results showed wider inward slanting (cat-like) eyes, a wider upturned nose and narrower downturned mouth. In the Caucasian cohort, narrower and wide set eyes, a narrower downturned nose with anteriorly displaced alare, a wider downturned mouth and posteriorly set chin were shown. The Caucasian cohort demonstrates similar dysmorphology as described in the literature. Published data for the African cohort is lacking. The nearest mean and k- nearest neighbour classifiers had the highest accuracy in the African and Caucasian groups respectively, with 71% and 77% correct classification. The efficacy of the stereophotogrammetry system introduced in this study has been shown, with craniofacial dysmorphology in schizophrenia successfully detected. Further studies with larger cohorts are recommended to attempt improved classification accuracy, but a platform now exists to pursue dysmorphology studies in other psychoses, such as bipolar disorder.

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Birkner, Luisa. "Vergleichende Untersuchungen zur Wiedergabegenauigkeit optoelektronischer berührungsloser und plastischer Abformungen weicher Gesichtsstrukturen." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-139636.

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Vergleichende Untersuchungen zur Wiedergabegenauigkeit optoelektronischer berührungsloser und plastischer Abformungen weicher Gesichtsstrukturen Universität Leipzig, Dissertation Problemstellung: Deformation der fazialen Weichgewebe bei liegenden Patienten, hervorgerufen durch schwerkraft- und materialgewichtabhängige Einflüsse der bei konventionellen Abformmethoden verwendeten Materialien Hydrokolloiden und Elas- tomere. Ziel: Vergleich der Wiedergabegenauigkeit weicher Gesichtsstrukturen bei konven- tionellen plastischen Abformmethoden und einem optischen, mechanischen berüh- rungsfreien dreidimensionalen fotorealistischen Modell. Material und Methode: Konventionelle Abformung bei 20 Probanden mit Hydrokolloid und Elastomer sowie ein optischer Gesichtsscan vom Mittelgesicht. Studienaufbau: Digitali- sieren der Gipsmodelle und Auswertung aller STL-Datensätze zum Vergleich zwischen plastischen und optoelektronischen Abformungen sowie die Evaluation der vorhandenen Abweichungen in 34 konstruierten Punkten. Statistik: Testen auf Normalverteilung und Varianzengleichheit zum Prüfen der Signifikanz mittels Zweistichproben-t-Test und Wilcoxon-Rangsummen-Test. Ergebnisse: Der allgemeiner Abformfehler zwischen optischem Scan und konven- tionellen Abformungen liegt bei 1,19 mm ± 0,32 mm mit Variationen bei den Ma- terialien Alginat 1,02 mm ± 0,24 mm und Silikon 1,36 mm ± 0,31 mm. Signifikante Unterschiede zwischen den Abformmaterialien zeigen sich in 6 von 34 Messpunkten (p < 0,05). Alginat weist tendentiell die besseren Ergebnisse auf und ruft weniger Weichgewebsveränderung hervor. Die beschriebenen Differenzen entstehen durch die Deformation der Weichgewebe bei der Gesichtsabformung. Bei den Punkten ohne statistische Signifikanz ist die Abformtechnik als sehr präzise zu betrachten. In gut skelettal-unterstützten Regionen zeigt Silikon in einigen Messpunkten geringere Abweichungen. Schlussfolgerung: Die Auswahl des Abformmaterials sollte in Abhängigkeit von der Ausgangssituation gewählt werden. Trotz der modifizierten Abformtechnik zeigen die Ergebnisse einen deutlichen Unterschied zwischen digital erfasstem dreidimensionalem Gesichtsscan und konventionellen Abformmethoden. Den optischen Systemen ist derzeit der Vorzug zu geben. Die Vorteile sind hinsichtlich noninvasiver, iterierender Aufnahmen, genauerer und effektiverer Analyse sowie CAD/CAM-Herstellung von Epithesen aus biokompatiblen Werkstoffen beachtlich.

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PUCCIARELLI, VALENTINA. "STEREOPHOTOGRAMMETRIC ANALYSIS OF THE HUMAN FACE: A TOOL FOR MODERN MORPHOLOGISTS." Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/543710.

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The introduction of new technologies has provided, in the last years, a significant contribution to anthropometry. In this context, facial anthropometry has greatly benefited from optical instruments such as laser scanners and stereophotogrammetry. The latter technique has proven to be accurate, repeatable and fast; therefore, taking into consideration its non-invasive nature, it has been increasingly applied to medicine, due to the relevant support that anthropometry can provide to this field. A facial anthropometric assessment can provide reliable morphometric details about the presence of deformities and peculiar features connected to underlying pathological conditions, not always easily recognizable. In the case of certain neurologic diseases, it can also provide new insights about the genotype/phenotype correlation taking the close relationship between facial and cerebral development into consideration. Furthermore, the three-dimensional morphometric evaluation of the face can reveal objective parameters useful for the planning and assessment of maxillo-facial and dental treatments, thus facilitating the clinical decisions and increasing the patients’ compliance. The facial morphometric evaluations presented in the current thesis were performed through the VECTRA M3 3D stereophotogrammetric system (Canfield Scientific, Fairfield, NJ, USA). All the patients and control subjects involved were marked with a set of facial landmarks (adapted according to the different study purposes), before the acquisitions. Once the three-dimensional models were obtained, they were elaborated through the software of the stereophotogrammetric system. Data were analysed through different statistical techniques, according to the type of study executed. The morphometric evaluations were divided in two groups: facial morphometric analyses performed through a landmark-based approach and through a surface- based approach. The first group included the studies: 1) “The face of adult patients affected by Dravet Syndrome: a 3D stereophotogrammetric preliminary assessment”, 2) “3D Craniofacial morphometric analysis of GLUT-1 DS patients” and 3) “Stereophotogrammetric analysis of a case of holoprosencephaly”. The second group included the studies: 4) “3D stereophotogrammetric assessment of labial symmetry in a girl treated for a lymphatic malformation” and 5) “Facial reanimation assessment performed through 3D-3D superimposition: a new method”. 7 For both assessed syndromes, study 1 and 2 allowed the individuation of facial features common among the patients, whose recognition can have a role in the diagnosis of the disease, both in children (study 2) and in adult cases (study 1). Study 3 allowed the identification of the presence of dysmorphic facial features in a girl affected by holoprosencephaly with an apparently normal aspect, thus sustaining the potential of the 3D stereophotogrammetric facial analysis in the morphometric characterisation of the face. Study 4 and 5 showed the usefulness of this technique for performing an objective surgical follow-up and final evaluation of maxillo-facial treatments, helping clinicians in their decisions and motivating the patients. In conclusion, all the studies sustained the usefulness, for medical purposes, of an anthropometric assessment of the human face, performed through a three-dimensional stereophotogrammetric analysis. Moreover, they highlighted its applicability to different categories of patients, including children and people with intellectual disability; thus again justifying the increasing diffusion of stereophotogrammetry in clinical and research centres.

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Uffner, Neil E. "THREE-DIMENSIONAL ASSESSMENT OF THE EFFECTS OF EXTRACTION ON THE SMILE IN CLASS II HIGH AND LOW MANDIBULAR PLANE ANGLE PATIENTS." Master's thesis, Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/219332.

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Oral Biology M.S. The annals of orthodontics are filled with studies aimed to understand how extraction orthodontic treatment might change the face. Although many studies have addressed profile changes due to extraction treatment, fewer studies have focused on how extractions change a patients smile. With the advent of surface imaging systems such as 3dMD, it is now possible to visualize the smile, and any changes incurred during orthodontic treatment, in three dimensions. Subjects for this study were chosen from the pool of 11-18 year old patients treated at the Podray Orthodontic Clinic at the Temple University Kornberg School of Dentistry. Subjects were Cl II patients, and must have been treated with either extraction of any combination of premolars or treated without extraction. Subjects were divided into four experimental groups based on two characteristics- mandibular angle (those with angles greater than 28o versus those with angles less than 28o) and treatment (extraction versus non-extraction). The resulting groups were separated as follows: high-angle extraction patients (n=8), low-angle extraction patients (n=6), high-angle non-extraction patients (n=7), and low-angle non-extraction patients (n=15). For each subject initial and final 3dMD images were superimposed using 3dMD Vultus software. A color histogram was constructed to visualize changes during treatment. The cheeks, commissures, upper and lower lips, chin, and nose, were also landmarked, and the changes in these landmarks were calculated. Volume changes were also calculated between pre and post treatment 3D data. Results showed that the lower lip and right commissure changes between high-angle extraction and non-extraction groups were statistically significant. A qualitative analysis of the histograms further supported these findings. In general, a greater change in soft tissue landmarks and soft tissue volumes could be seen in high-angle patients than low-angle patients. Differences in the changes that result from treatment type (extraction vs. non-extraction) were seen in the high-angle group. In contrast, similar changes result from treatment type (extraction vs. non-extraction) in the low-angle groups. Furthermore, the lip changes seen in extraction patients upon smiling are very similar to those changes seen in the same patient in repose. Most interestingly, soft tissue differences of the face due to treatment, growth, or both, seem to disappear upon smiling, with the exception of the lips. Qualitative assessment of these changes in the smile might be a more appropriate method for identifying soft tissue changes than statistical analyses. Similar studies with larger sample sizes are a promising direction for future research. Temple University--Theses

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Osborne, Patrick Rocha. "Avaliação retrospectiva do volume facial em pacientes submetidos a cirurgia ortognática utilizando a estereofotogrametria (foto 3D)." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/58/58136/tde-01032018-164843/.

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O objetivo deste estudo foi determinar as variações de volume pós-operatórias associadas à cirurgia ortognática, com base nas variáveis tempo, gênero, idade e lado da face. Foram avaliadas fotografias tridimensionais de dezoito pacientes submetidos simultaneamente às osteotomias Le Fort I e sagital do ramo mandibular bilateral. As imagens foram obtidas por meio do aparelho Vectra® M3 (Canfield, NJ, EUA) e capturadas nos períodos pós-operatórios de: uma semana (1S), um mês (1M), dois meses (2M), seis meses (6M) e um ano (1A). A foto obtida no período 1A foi utilizada como base de comparação para as demais (1S, 1M, 2M e 6M). O maior volume facial foi observado 1 semana após a realização da cirurgia ortognática (47,11 cm3, DP = 30,5 cm3), e neste período os homens apresentaram valores mais elevados (67,27 cm3, DP = 33,54 cm3) em relação as mulheres (30,98 cm3, DP = 15,25 cm3) e o lado direito (26,58 cm3, DP = 17,22 cm3) maior que o esquerdo (20,52 cm3, DP = 14,93 cm3). A regressão do volume mais expressiva ocorreu entre a primeira semana e o primeiro mês de pós-operatório (58,9%). Não foram observadas diferenças significantes entre as faixas etárias analisadas. The purpose of this retrospective study was to determine postoperative volume differences associated with orthognathic surgery, controlling for time, gender, age and side of face. Three-dimensional (3D) photographs were analyzed of eighteen patients submitted to simultaneous Le Fort I + Bilateral Sagittal Split osteotomies. The images were obtained using a Vectra® M3 device (Canfield, NJ, USA) and were captured postoperatively, at one week (1S), one month (1M), two months (2M), six months (6M) and one year (1A). The photo taken at 1A was used as the basis of comparison for the other photos (1S, 1M, 2M, 6M). Greatest facial volume was observed at one week after surgery (47,11 cm3, DP = 30,5 cm3), with men in this period showing higher values (67,27 cm3, DP = 33,54 cm3) than women (30,98 cm3, DP = 15,25 cm3) and the right side (26,58 cm3, DP = 17,22 cm3) higher than the left (20,52 cm3, DP = 14,93 cm3). The most extensive facial volume resolution occurred between the first week and the first month; postoperatively (58,9%). No significant difference was found between age groups.

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Defay, David Kay. "3D facial analysis: unaffected parents of individuals with cleft lip/palate." Thesis, University of Iowa, 2011. https://ir.uiowa.edu/etd/944.

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The purpose of this work is to study phenotypic craniofacial traits of unaffected parents of individuals with nonsyndromic cleft lip with or without palate (NSCL/P). In order to evaluate these craniofacial traits, three dimensional photographs were obtained and landmarked to compare the sample of unaffected parents with a control sample. The sample was comprised of 40 unaffected fathers, 25 control males, 84 unaffected mothers, and 34 control females. Twenty-four three-dimensional landmarks were exported for analysis for each subject. For the purposes of this study, nine euclidean distances were subjected to a discriminant function analysis to evaluate their ability to discriminate between an unaffected parent and a control. In both the male and female analysis, certain craniofacial measurements correctly and significantly discriminated between unaffected parents and controls. It appears that certain facial traits are subclinical markers for enhanced genetic susceptibility to nonsyndromic cleft lip with or without palate.

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Rossetti, A. "ANALISI TRIDIMENSIONALE DELLA MORFOLOGIA FACCIALE CON L'UTILIZZO DELLA STEREOFOTOGRAMMETRIA." Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/168376.

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Three dimensional analysis of facial morphology using stereophotogrammetry The human face has been largely evaluated from the quantitative point of view in medical literature, using manual anthropometry, photography and radiography. The limits of these techniques are: long-time procedure in analogic data acquisition for manual anthropometry, bi-dimensionality for photography, invasivity for radiography. Stereophotogrammetry promises to be a new, digital, three-dimensional, non invasive technique for evaluating the human face, in several medical fields, such as maxillofacial surgery, aesthetic surgery, orthodontics, prosthodontics, general dentistry. The instrument is based on the binocular vision: two pairs of cameras, with known reciprocal distance and angulation, capture two different images of the same object, allowing its three-dimensional virtual reconstruction, using a dedicated software. The current thesis proposes and evaluates three different applications of this technology: the first study proposes a new possibility in medical imaging, merging the superior dental arch with the 3D image of the face in a unique image. The procedure resulted accurate and reliable, with a relative error magnitude <1.2%, in comparison with direct anthropometry. Applications are possible in the diagnosis and treatment of the dento-facial pathologies, in the monitoring of the orthodontic and orthopaedic therapies. The second study investigates the morphological changes of the facial soft tissues, after dental additive modifications. A dental treatment was simulated by applying veneers with different thicknesses (1 and 2 mm) to the vestibular surfaces of the superior anterior teeth and the resulting new position of the facial tissues was compared with the baseline one. The highest amount of morphological response (from 0.4mm to 0.6mm) was concentrated in a central area around the upper and the lower lip, even using 1mm thickness. The study can help physicians to formulate more complete diagnosis and treatment planning, especially in the aesthetic field of dento-labial region. The third study is an anthropometric and aesthetic-related research of human face proportions, including references to the golden ratio. Out of a population of 600 subjects, who underwent a stereophotogrammetric facial acquisition, two groups of 20 subjects were extracted and divided in “very attractive” and “not attractive” by a panel of 4 judges. 10 facial ratios were compared between the two groups, using an ANOVA test, in order to find differences based on gender and attractiveness. The values of the facial ratios were also compared to the golden ratio (1.618) using a paired t-test. No significant differences were found in any group. Only a few facial ratios have significant relationships with the golden ratio. Beyond the technical results, the study is an example of how much helpful stereophotogrammetry could be in anthropometric research. In conclusion, stereophotogrammetry proved to be a reliable technique in several face-related medical fields. Its characteristics of high-quality imaging, three-dimensionality, non-invasive and easy-to-use procedure will ensure its wider diffusion and affordability in the future.

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MENEZES, M. DE. "THREE-DIMENSIONAL FACIAL ANTHROPOMETRY." Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150157.

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The use of 3D surface technology is progressively increasing in health clinics and research centers. Methods of capturing 3D facial surface may obtain more imaging information providing a reliable and fast analysis. Stereophotogrammetry is a promising method of soft-tissue evaluation that allows reliable analysis of craniofacial deformities, providing fundamental parameters to plan and evaluate dental treatments and maxillofacial surgery, so improving the multi-disciplinary and multi-species studies of genotype–phenotype correlations through simple and precise measurements. In the current study, photogrammetry/stereophotogrammetry systems were used to evaluate soft-tissue facial morphology and dental casts. Three-dimensional images were collected and rebuilt in 3D, using software for rendering images to establish, analyze and compare morphology features of craniofacial structures, and to assess the usage and limitations of these devices. The use and investigation of this system were divided in 4 studies: 1) A photographic system for the three-dimensional study of facial morphology; 2) Accuracy and reproducibility of a 3D stereophotogrammetry imaging system; 3) Digital dental cast placement in 3-dimensional, full-face reconstruction: A technical evaluation and 4) Unilateral Cleft Lip and Palate (UCLP): a 3D evaluation. The current studies found the used 3D image systems both accurate and repeatable. The 3D devices and the methods analyzed in these studies could therefore be usefully used for clinical analysis in maxillofacial, plastic and esthetic surgery, as well as in all dental fields. The 3D stereophotogrammetric systems have several advantages over direct anthropometry and gradually are becoming into more accessible cost, replacing classical methods to quantify surface topography.

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Bishop, Richard. "Applications of Close-Range Terrestrial 3D Photogrammetry to Improve Safety in Underground Stone Mines." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98920.

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The underground limestone mining industry is a small, but growing segment of the U.S. crushed stone industry. However, its fatality rate has been amongst the highest of the mining sector in recent years due to ground control issues related to ground collapses. It is therefore important to improve the engineering design, monitoring and visualization of ground control by utilizing new technologies that can help an underground limestone company maintain a safe and productive operation. Photogrammetry and laser scanning are remote sensing technologies that are useful tools for collecting three-dimensional spatial data with high levels of precision for many types of mining applications. Due to the reality of budget constraints for many underground stone mining operations, this research concentrates on photogrammetry as a more accessible technology for the average operation. Despite the challenging lighting conditions and size of underground limestone mines that has previous hindered photogrammetric surveys in these environments, over 13,000 photographic images were taken over a 3-year period in active mines to compile these models. This research summarizes that work and highlights the many applications of terrestrial close-range photogrammetry, including practical methodologies for implementing the techniques in working operations to better visualize hazards and pragmatic approaches for geotechnical analysis, improved engineering design and monitoring. M.S. The underground limestone mining industry is a small, but growing segment of the U.S. crushed stone industry. However, its fatality rate has been amongst the highest of the mining sector in recent years due to ground control issues related to ground collapses. It is therefore important to improve the engineering design, monitoring and visualization of ground control by utilizing new technologies that can help maintain safe and productive underground stone operations. Photogrammetry and laser scanning are remote sensing technologies that are useful tools for collecting three-dimensional spatial data with high levels of precision for many different mining applications. Due to the reality of budget constraints for many mining operations, this research concentrates on photogrammetry as a more accessible technology for the average operation, despite the challenging lighting conditions and expansive size of underground limestone mines that has previous hindered photogrammetric surveys in these environments. This research focuses on the applications of photogrammetry in underground stone mines and practical methodologies for implementing the techniques in working operations to better visualize hazards for improved engineering design and infrastructure management.

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Memier, Michel. "Stéréophotogrammétrie numérique : calcul de M.N.T. par corrélation automatique d'images SPOT." Université Joseph Fourier (Grenoble), 1991. http://www.theses.fr/1991GRE10083.

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La reconstruction tridimensionnelle d'une surface à partir de deux images prises de points de vue différents nécessite d'une part la connaissance de la géométrie du capteur (géométrie interne et position spatiale), et d'autre part la reconnaissance de points homologues (corrélation). L'objet de cette thèse est la production de modèles numériques de terrain (MNT) à partir d'images du satellite européen SPOT. La modélisation géométrique est fondée sur l'approche de Guichard qui aboutit à des équations simples et rigoureuses. Les mêmes équations peuvent être utilisées pour l'orientation absolue du modèle (si l'on connaît des points d'appui) ou l'orientation relative en partant simplement de points homologues. L'aboutissement de la modélisation permet de générer un redressement des images sur un plan spécifique (épipolaire), permettant de faciliter la phase suivante de mise en correspondance. La corrélation est abordée selon des approches purement numériques (corrélation de vignettes à partir de considérations statistiques globales) ou selon une approche plus topologique, essayant de mettre en correspondance des éléments de frontières. Quelques applications des MNT sont présentées (représentation en courbes de niveaux perspectives)

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Pisoni, L. "THREE-DIMENSIONAL ANALYSIS OF PALATE MORPHOLOGY IN UNILATERAL CLEFT LIP AND PALATE CHILDREN." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/252652.

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Abstract Object: The aim of this study was to evaluate the effects of the orthopedic treatment (performed either by using active or passive plates) and the subsequent surgical treatment on the palatal size and shape of dental casts of patients with unilateral cleft lip and palate (UCLP). Material and methods: 96 palatal cast models, obtained from 32 neonatal patients with UCLP, attending the Fundacion Clinica Noel de Medellin (Colombia) were analyzed using a 3D stereophotogrammetric system in three different time points: before the orthopedic treatment, before and after cheiloplasty. Half of the patients were treated with a passive plate, while the other patients received an active plate. The areas and volumes of the greater and minor segments were obtained using a new measurement protocol. Method repeatability both within and between operators was evaluated using the Paired Student’s t-test and the technical error of measurement (TEM). Area and volume measurements were compared with a three-way repeated measures analysis of variance (ANOVA) to determine differences between plates, alveolar segments and time. Results: No systematic measurement errors were found for both inter-operator and intra-operator’s tracings (p>0.05; TEM<0.32 cm2). No differences were found for the kind of plates (active or passive). Significant differences were found in alveolar segment and time in both area and volume (p<0.01). Conclusions: We showed that area and volume measurement by the 3D stereophotogrammetric system was a repeatable and reliable method of evaluating the stone casts of patients with UCLP. Data obtained were helpful to quantify changes occurring in maxillary arches of UCLP patients after orthopedic and surgical treatments. However, further investigation is needed to especially evaluate the effects of plates, increasing the number of additional time points and expanding the number of patients.

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Codari, M. "COMPUTER AIDED FEATURE EXTRACTION IN 3D ORO-MAXILLO-FACIAL IMAGES." Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/468280.

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Aim: Recently, maxillofacial imaging has drastically evolved thanks to the development of dedicated imaging techniques. The complex anatomy of the maxillofacial region requires the use of different image modalities, demanding the development of dedicated image analysis procedures. This doctoral thesis aims at explore the possible applications of image processing techniques for maxillofacial applications. Hard tissue imaging: In this chapter, we propose different studies that focused on image segmentation, registration and artifact reduction applied to the automatic extraction of hard tissue structures in CBCT data. The procedure involves an adaptive, cluster-based segmentation of bone tissues followed by an intensity-based registration of an annotated reference volume onto a patient CBCT head volume. Automatic segmentation shows a high accuracy level with no significant difference between automatically and manually determined threshold values. The overall median localization error was equal to 1.99 mm with an interquartile range (IQR) of 1.22-2.89 mm. The second study aims to objectively compare the influence of different image parameters on metal artifact generation. After a fully automatic segmentation and image registration, the effect on metal object segmentation and background image noise was evaluated. Results showed that metal object segmentation is highly influenced by the device and material factor, while background noise was more affected by the devices and the FOV parameters compared to the used material. Then, in the third study, in order to improve the automatic extraction of craniofacial features and cephalometric landmarks, we designed a metal artifacts reduction (MAR) algorithm. The new MAR step is fully integrated with our landmark detection algorithm and works on both projection and image domain and allows the automatic detection of the corrupted portion of the image, thus preserving image details. The algorithm was tested on 17 CBCT volumes with a total number of 245 analysed VOIs and reduction of SD values in not metallic voxels was used as image metric. In our dataset, the proposed MAR algorithm always decreased the voxel intensity SD in the examined VOIs, thus showing a significant metal artifact reduction in a fully automatic way. Finally, in order to improve the segmentation quality in the mandibular condyle region, which is usually affected by large amount of noise, a dedicated segmentation approach was developed. Also this algorithm is integrated with the hard tissue segmentation approach and it is based on patient adaptive thresholding and contrast enhancement techniques. The algorithm was tested in vitro on a series of CT and CBCT scans of a dried human mandible. To reproduce soft-tissue attenuation, a cupper filter was used. The proposed automatic segmentation algorithm allows to improve the quality of the trabecular bone segmentation, significantly reducing the overestimation of the segmented bone. Soft tissue imaging: In this section, the application of stereophotogrammetric systems and laser scanners for the development of computer aided approaches for facial morphology evaluation was evaluated. In the first study, we present a new quantitative method to assess symmetry in different facial thirds, objectively defined on trigeminal distribution branches territories. Seventy subjects (40 healthy controls and 30 patients affected by monolateral facial palsy) were acquired with a stereophotogrammetric system and the level of asymmetry was evaluated, RMSD was used as asymmetry metric. Results show a high average reproducibility of area selection and significant differences in RMSD values between controls and patients for all the thirds. No significant differences were found on different thirds among controls, while significant differences were found for upper, middle and lower thirds of patients. The proposed method provides an accurate, reproducible and local facial symmetry analysis. The second study aims to develop an imaging technique that allows to integrate the information about patient dentition together with the stereophotogrammetric reconstruction of the face, providing an un-invasive way to assess the morphology of facial soft tissues in relation to teeth. The proposed algorithm is based on several surface registration steps, initialized by a landmark registration step. To validate the proposed method, CBCT images were analysed and a series of dentofacial distances were calculated. The high values of percentage of corresponding point and a median distance of 0.59 mm prove the accuracy of the registration progress. Statistical analysis shows no significant differences between distanced calculated on CBCT image or on face and dental surfaces, except for one distance. Upper airway imaging: In this last section, a new image analysis method was developed to assess whether three-dimensional morphometric parameters could be useful in nasal septal deviation (NSD) diagnosis and, secondarily, whether CBCT could be considered an adequate imaging technique for the proposed task. Forty-six CBCT scan were segmented using ITK-Snap in order to obtain the 3D model of patient upper airway and compute four morphological parameters septal deviation angle (SDA), percentage of volume difference between right and left side of the nasal airways, nasal airway total volume and a new synthetic septal deviation index (SDI). Principal component analysis (PCA) was used to unveil relationships between each variable and the global nasal airway variability. Among the analysed parameters, SDI seemed to be the most suitable for the quantitative ssessment of NSD, and CBCT allowed accurate assessment of airway morphology. Conclusion: In conclusion, we proved that the application of image processing techniques may help in the development of new diagnostic tools. This PhD thesis has helped creating a good basis for future studies on the application of imaging techniques in oral and maxillofacial applications.

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Morel, Jean-Claude. "Appareil de compression biaxiale et sols renforcés." Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10017.

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La mise au point d'un appareil de compression biaxiale, appele biaxial, permettant d'ecraser des materiaux granulaires en deformations planes, sous confinement, a permis de faire l'etude de deux types de materiaux renforces. Pour le micro-renforcement, il s'agit d'un sable renforce par des microgrilles (elements discrets) melangees d'une maniere aleatoire au sable d'hostun rf. Une modelisation de la cinematique de bande de cisaillement est proposee et validee par des essais de cisaillement direct avec une grande boite de cisaillement. L'etude au biaxial a permis de montrer l'influence de la concentration massique en renforcement. L'utilisation de la methode de stereophotogrammetrie a permis de caracteriser la localisation en bande de cisaillement qui intervient a peu pres dans les memes conditions que dans le sable seul, mais qui ne se traduit pas par une chute des contraintes globales dans le materiau, au contraire il y a une augmentation continue de celles-ci jusqu'a la fin de nos essais: les microgrilles sont mobilisees par les bandes de cisaillement. Une etude au triaxial de revolution, sous sollicitations cycliques, montre que le sable renforce presente des tassements plus faibles et une meilleure resistance que le sable seul ; le comportement post cycle du materiau renforce est modifie. Pour le macro-renforcement, le meme sable, renforce par des nappes de geotextiles, non tissees, avec differentes orientations par rapport a l'axe des contraintes principales majeures, est teste au biaxial. La disposition horizontale des nappes est celle qui apporte le plus grand renforcement au materiau alors que des inclinaisons proches de l'inclinaison des plans de glissement du sable seul, diminue la resistance du materiau composite, par rapport au sable seul. Les deformations locales au sein de l'echantillon sont analysees ainsi que les mesures des deplacements relatifs des nappes par rapport au sable grace a une adaptation de la methode stereophotogrammetrique

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Naaim, Alexandre. "Modélisation cinématique et dynamique avancée du membre supérieur pour l’analyse clinique." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1014/document.

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Les Artefacts de Tissus Mous (ATM) sont actuellement une des limitations principales pour la mesure du mouvement du membre supérieur avec les techniques actuelles d'analyse du mouvement. L'optimisation multi-segmentaire (OMS) a déjà prouvé son efficacité pour la mesure du mouvement du membre inférieur. Afin d'avoir la meilleure correction possible, il est nécessaire d'utiliser des modèles d'articulation proches de l'anatomie. L'objectif de cette thèse a donc été de développer et de valider un modèle du membre supérieur qui pourrait être utilisé pour la correction des ATM par OMS. De nouveaux modèles en boucle fermée de l'avant-bras et de la ceinture scapulaire ont ainsi été développés accompagnés d'un nouveau modèle de l'articulation scapulo-thoracique imposant à la scapula d'être tangente à un ellipsoïde modélisant le thorax. Ces nouveaux modèles ont été confrontés aux modèles courants de la littérature à travers une étude avec vis intra-corticales sur cadavre et in vivo sur sujets asymptomatiques. Des niveaux d'erreur similaires ont été observés pour tous les modèles quant à leur capacité de corriger les ATM et d'imiter la cinématique osseuse. Les nouveaux modèles semblent cependant beaucoup plus intéressants dans une perspective de développement d'un modèle musculo- squelettique. En effet, le modèle d'avant-bras autorise à la fois d'avoir le mouvement du radius et de l'ulna tandis que le modèle scapulo-thoracique représente mieux la contrainte existant entre le thorax et la scapula. En résumé, cette thèse a permis de développer un modèle complet proche de l'anatomie du membre supérieur permettant de corriger les ATM en utilisant une OMS. Bien que la correction des ATM obtenue n'est pas aussi satisfaisante qu'espérée, l'utilisation de cette approche pour le développement de futurs modèles musculo-squelettique a été validée Soft Tissue Artefact (STA) is one of the most important limitations when measuring upper limb kinematics through marker-based motion capture techniques, especially for the scapula. Multi Body Optimisation (MBO) has already been proposed to correct STA when measuring lower limb kinematics and can be easily adapted for upper limb. For this purpose, the joint kinematic constraints should be as anatomical as possible. The aim of this thesis was thus to define and validate an anatomical upper limb kinematic model that could be used both to correct STA through the use of MBO and for future musculoskeletal models developments. For this purpose, a model integrating closed loop models of the forearm and of the scapula belt have been developed, including a new anatomical-based model of the scapulothoracic joint. This model constrained the scapula plane to be tangent to an ellipsoid modelling the thorax. All these models were confronted to typical models extracted from the literature through cadaveric and in vivo intracortical pins studies. All models generated similar error when evaluating their ability to mimic the bones kinematics and to correct STA. However, the new forearm and scapulothoracic models were more interesting when considering further musculoskeletal developments: The forearm model allows considering both the ulna and the radius and the scapulothoracic model better represents the constraint existing between the thorax and the scapula. This thesis allowed developing a complete anatomical upper limb kinematic chain. Although the STA correction obtained was not as good as expected, the use of this approach for a future musculoskeletal models has been validated

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Mokni, Moncef. "Relations entre déformations en masse et déformations localisées dans les matériaux granulaires." Grenoble 1, 1992. http://www.theses.fr/1992GRE10185.

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On presente une etude experimentale de la localisation de la deformation en bandes de cisaillement dans les materiaux granulaires et une etude theorique de la sensibilite du modele cloe a certains parametres. L'etude experimentale est realisee en deux volets: 1) le premier volet de l'etude concerne le phenomene de la localisation de la deformation au triaxial axisymetrique, avec visualisation quantitative de l'apparition et du developpement de la localisation au cours de l'essai par la methode tomodensitometrique scanner a rayons x. De nouveaux elements ont ete apportes concernant l'influence des conditions aux limites et l'existence d'une densite limite dans les bandes de cisaillement en grande deformation. 2) le deuxieme volet de l'etude concerne la localisation a l'appareil biaxial en deformation plane. On analyse l'influence de quelques facteurs importants (geometrie, granulometrie, compacite) sur l'apparition et le developpement de la localisation en conditions drainees. En revanche, des elements complementaires interessants sont presentes concernant la localisation au biaxial en regime non draine. La partie theorique concerne la prediction de la localisation par la loi de comportement cloe. Une etude de la sensibilite du modele cloe a certaines constantes internes est presentee. Une modelisation des essais de deformation plane non drainee est realisee. Les resultats experimentaux presentes dans le cadre de ce travail constituent une base de donnees d'identification de la loi cloe et en particulier des modules de cisaillement

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Lallemant, Marine. "Etude du comportement des tissus périnéaux à l’accouchement : vers un modèle patiente spécifique." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. http://indexation.univ-fcomte.fr/nuxeo/site/esupversions/c70b5126-d4ff-4d1d-adb1-d1d8a6693dca.

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Les déchirures périnéales, quelle que soit leur sévérité, peuvent être source d’une morbidité physique et psychologique en post-partum immédiat et au long terme. Ces lésions concernent environ 60% des femmes. A ce jour, la survenue d’une déchirure périnéale lors de l’accouchement reste imprévisible et encore mal comprise sur le plan biomécanique. L’objectif global des travaux réalisés dans le cadre de cette thèse était d’améliorer nos connaissances sur le comportement des tissus constituant le périnée à l’accouchement et d’obtenir leurs propriétés biomécaniques à travers trois approches complémentaires. La première approche était expérimentale et ex vivo. Les propriétés mécaniques du périnée porcin ont été étudiées à l’aide d’essais de traction uni-axiale, d’élastographie et de stéréophotogrammétrie à l’état de base puis lors d’une déformation à l’aide d’un ballon tracté au travers d’un vagin porcin afin de simuler un accouchement. La deuxième approche était clinique. Un essai clinique exploratoire a été mené pour étudier in vivo des propriétés mécaniques et la déformation du périnée pendant la grossesse et à l’accouchement à l’aide de l’élastographie et de la stéréophotogrammétrie chez des femmes enceintes. La troisième approche était numérique. L’ensemble des données mécaniques obtenues par imageries et des mesures cliniques ont été intégrées dans un modèle numérique Perineal tears, regardless of their severity, can be a source of physical and psychological morbidity in the immediate postpartum period and in the long term. Such injuries are experienced by approximately 60% of all women. To date, the occurrence of a perineal tear during childbirth remains unpredictable and is still poorly understood from a biomechanical perspective. The overarching objective of this thesis was to improve our knowledge of the biomechanical behaviour of the perineal tissues during childbirth and to obtain their biomechanical properties through three complementary approaches. The initial approach was experimental and ex vivo. The mechanical properties of the porcine perineum were investigated using uniaxial tensile tests, elastography and stereophotogrammetry in the basal state, then during deformation with a balloon pulled through a porcine vagina, which was used to simulate the processes occurring during childbirth. The second approach was clinical. An exploratory clinical trial was conducted to study in vivo the mechanical properties and deformation of the perineum during pregnancy and childbirth using elastography and stereophotogrammetry in pregnant women. The third approach was numerical. All the mechanical data obtained from imaging and clinical measurements were incorporated into a numerical model

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Stančík, Petr. "Optoelektronické a fotogrammetrické měřicí systémy." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-233413.

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Dissertation deals with analysis and design of optoelectronic and photogrammetric measuring systems. Specific design of optoelectronic contactless flat object area meters with analysis of attainable measurement accuracy is described. Next part is dedicated to stereophotogrammetry - principles of 3D reconstructions, methods of camera self-calibration and matching points in images are described. The analysis of attainable accuracy of monitored parameters is discussed too. Finally, the test program with implemented described routines is introduced. This test program enables practical aplication of stereophotogrammetric system for taking spatial coordinates of 3D objects.

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Chung, Vivian W. J. "Leveraging the use of existing C-arms for Roentgen stereophotogrammetric analysis." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/56273.

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“You can’t improve it unless you can measure it” is a common sentiment in engineering. For total knee replacement patients, failed implants requiring revision surgery is a significant risk. Our long-term goal, therefore, is to develop and evaluate a protocol that will allow us to accurately measure the full 3D position of an implant in the early post-surgical period in order to detect signs of relative motion occurring between implant and bone. By doing this, we will be able to gain insights into the failure mechanisms behind total knee replacement implants. The 'gold standard' method for measuring relative motion is known as Roentgen Stereophotogrammetric Analysis (RSA) – a technique which extracts 3D information about the implant and bone positions from two roughly orthogonal radiographs. This information can be used to quantify the migration of an implant over time to submillimeter accuracy, a metric that has been shown to reliably predict implant longevity in patients (Pijls 2012). Unfortunately, commercial RSA systems are expensive, which has limited their use in clinical settings. Our goal in this project was to develop an RSA protocol based on C-arm fluoroscopy machines, many of which already exist in most hospitals. We successfully developed such a protocol and evaluated its accuracies and precisions through a series of phantom-based verifications. Results were highly promising: accuracies ranged between -39 to 11 μm for translations and -0.025 to 0.029° for rotations, while system precisions ranged between 16 to 27 μm and 0.041 to 0.059°. This performance was comparable to RSA systems in the literature, where traditional and more expensive radiographic equipment was typically employed. In addition, inter-rater reliability tests also showed a high degree of correlation (ICC > 0.999) between two raters who were trained to use the protocol. We conclude that we have developed an RSA protocol appropriate for measuring relative motion of knee replacement implants in phantoms and cadaveric specimens by leveraging the use of existing C-arm technology. This research places us in position to further develop the protocol for use in extensive prospective clinical assessments – research that can potentially drive future improvements in surgical technique and implant design. Applied Science, Faculty of Graduate

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Ruspi, Maria Luisa. "Studio della cinematica del nuoto a stile libero attraverso sensori inerziali." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/9952/.

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Analisi cinematica delle fasi del nuoto, velocità in vasca e body roll attraverso l'uso di sensori inerziali. Implementazione di innovativi algoritmi di calcolo con l'utilizzo del filtro di Kalman 3D, matrici di rotazione e quaternioni per la determinazione dei parametri fondamentali del nuoto e della posizione del polso nel sistema di riferimento di torace. Confronto dei risultati ottenuti mediante i diversi algoritmi e loro validazione con quelli ottenuti con l'uso della stereofotogrammetria. Gli algoritmi possono essere generalizzati ad altri gesti motori.

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Tillard, Dominique. "Etude de la rupture dans les géomatériaux cohésifs : application à la marne de Beaucaire." Grenoble 1, 1992. http://www.theses.fr/1992GRE10211.

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Pour juger de la pertinence du concept de bande de cisaillement applique a la rupture des roches aussi bien dans le domaine fragile que ductile, deux methodes de suivi de la deformation lors d'essais homogenes ont ete mises en uvre, a savoir, la tomodensitometrie et la stereophotogrammetrie de faux relief. Appliquees a des essais triaxiaux et biaxiaux realises avec ou sans confinement, ces deux methodes permettent, chacune a leur echelle, de cerner la transition d'une deformation diffuse a un mode localise avec apparition de fissures. Avec la stereocomparaison, l'ouverture de fissures, leurs interactions et leur contribution a la deformation globale peuvent entre autres etre quantifiees. Le geomateriau cohesif qui a ete l'objet d'une telle etude est la marne de beaucaire, une roche tendre saturee finement grenue dont la pression de consolidation est de 5 mpa. La rupture de type fragile avec propagation brutale en mode de cisaillement d'une macro-fissure que l'on observe en compression simple et sous tres faible confinement (0. 05 ou 0. 1 mpa) a pu etre analysee de meme que la localisation en bandes de cisaillement contractantes obtenue sous 0. 25 mpa ou la densification du materiau observee sous plus fort confinement (1 mpa). Dans la mesure ou la notion de bande de cisaillement a ete, a partir de nos resultats experimentaux, jugee adequate pour decrire le comportement a la rupture de la marne de beaucaire dans les domaines de contraintes consideres, une analyse de bifurcation en mode localise visant a predire le seuil de localisation et l'orientation de la bande de cisaillement, a ete conduite avec une loi incrementale non lineaire particulierement souple, la loi cloe. Pour mener a bien une telle analyse sur un cas concret: le trou de forage, les parametres de cloe pour la marne de beaucaire ont d'abord ete identifies sur des chemins triaxiaux et biaxiaux elementaires

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Baring, Toby. "Integrity of the repaired rotator cuff; a roentgen stereophotogrammetric analysis with ultrasound comparison." Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529381.

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26

Hough, Jan K. "Assessment of and improvements to a stereophotogrammetric patient positioning system for proton therapy." Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/26784.

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Summary in English. Bibliography: pages 125-129. This thesis describes the construction and use of the facemask at the National Accelerator Centre (NAC) as used to both immobilise and position patients for precision proton radiotherapy. The precision achieved using the stereophotogrammetric (SPG) positioning system is measured, and the shortcomings and errors in using the facemask by the SPG system are measured and analysed. The implementation of improvements made to the SPG system is reported upon, and alternative means of both supporting the fiducial markers and immobilising the patient are investigated and evaluated. The accuracy of positioning a facemask using the SPG system is 1.4 mm and of positioning a newly designed frame is 1.6 mm. These measurements were made without using a patient. It is estimated that the total uncertainty of positioning a patient's tumour at the isocentre is 1.6 (1SD) mm using the facemask and it is estimated that the precision using the frame will be less than this value. The largest component of this error (1.39 mm) is due to the error in obtaining the CT scanner co-ordinates. These results are comparable to those obtained by other investigators. The movement of patient bony landmarks within the facemask was measured to be 1.0 ± 0.8 mm. Three main recommendations are that the CT scanner co-ordinating procedure be improved, the SPG computer program be rewritten in parts to achieve greater speed and accuracy, and that the new frame be used. The frame is easier to manufacture than the facemask and allows real time monitoring of the position of the patient's head by the SPG system thus allowing faster throughput of patients and better positioning quality control.

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Millington, Steven Andrew. "Quantitative stereophotogrammetric & MRI evaluation of ankle articular cartilage and ankle joint contact characteristics." Thesis, University of Nottingham, 2008. http://eprints.nottingham.ac.uk/10484/.

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Osteoarthritis and degenerative cartilage diseases affect millions of people. Therefore, there is huge interest in developing new therapies to repair, replace and/or regenerate cartilage. This necessitates advances in techniques which make earlier non-invasive diagnosis and objective quantitative evaluations of new therapies possible. Most previous research has focused on the knee and neglected the ankle joint. Hence, the aims of this thesis are to describe and quantify the geometric properties of ankle cartilage, to evaluate joint contact characteristics and develop techniques which allow quantitative measurements to be made in vivo. Chapters 3 and 6 describe the application of a high resolution stereophotography system for making highly accurate 3-D geometric models from which quantitative measurements of cartilage parameters and joint area contact can be made. Chapters 4 and 5 report the testing of image analysis algorithms designed to segment cartilage sensitive MR images. Work focused on initially on a semi-automated 2-D segmentation approach and subsequently on a pilot study of 3-D automated segmentation algorithm. The stereophotographic studies were highly accurately and demonstrated that ankle cartilage thickness is greater than previously reported with the thickest cartilage occurring where cartilage injuries are most commonly seen. Furthermore, joint contact area is larger than previously believed and corresponds to the regions of the thickest cartilage over the talar shoulders. The image analysis studies show that it is possible to accurately and reproducibly segment the thin cartilage layers of the ankle joint using a semi-automated approach. The feasibility of a fully automated 3D method for future clinical use is also shown. In conclusion this thesis presents novel methods for examining ankle articular cartilage in vitro and in vivo, showing that the thickest cartilage occurs in highly curved regions over the shoulders of the talus which correspond to regions of greatest contact. Importantly, the image analysis techniques may be used for future clinical monitoring of patients sustaining cartilage injuries or undergoing cartilage repair therapies.

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Aarnivala, H. (Henri). "Deformational plagiocephaly:prevalence, quantification and prevention of acquired cranial asymmetry in infants." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526215488.

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Abstract The recommendation for infants to sleep supine has decreased the incidence of sudden infant death syndrome by more than a half, but as another consequence, a dramatic rise has been observed in the incidence of acquired cranial asymmetry (deformational plagiocephaly, DP). According to recent data, almost half of otherwise healthy infants are affected by some degree of DP at 7 to 12 weeks of age, and especially in the USA and some Central European countries, major effort is put into treatment of severe DP. However, little is known of the prognosis of DP in the absence of intervention, and although primary preventive strategies are often recommended, a lack of evidence on the effectiveness of such measures persists. Furthermore, although 3D imaging is nowadays frequently used on infants with DP, no data is available on the accuracy of the measurements used to quantify cranial asymmetry. In the present study, the efficacy of a primary preventive program in reducing the incidence of DP was tested in a randomized, controlled trial. The course of DP in the absence of active treatment was studied throughout the first year of life, and factors impacting the prognosis of DP were investigated. The diagnostic accuracy of four 3D stereophotogrammetry-based measurements was also analyzed and compared, with a goal of determining their optimal cut-off values for DP. DP was less prevalent and less severe in the intervention group infants at the end of the RCT (3 months). The point prevalence of DP peaked at 3 months, whereafter spontaneous improvement in DP was seen throughout the follow-up period until 12 months of age. A preferential infant head position at 3 months was the strongest predictor of a subsequently unfavorable course of DP. Cranial asymmetry seen at birth was transient, and none of the older infants with torticollis had presented neck imbalance at birth, but rather appeared to develop the condition postnatally concomitantly with DP. Although all studied asymmetry-related measurements performed well regarding diagnostic accuracy, OCLR produced the most accurate classification of DP. In conclusion, primary preventive guidelines would likely aid in reducing the burden from both DP itself and associated healthcare costs, although substantial spontaneous improvement from DP can usually be expected. The cut-off values defined for the asymmetry-related measurements have clinical implication in both making the diagnosis of DP and determining the target outcomes for treatment Tiivistelmä Imeväisten nukuttaminen selällään on vähentänyt kätkytkuolemien määrää alle puoleen aiemmasta, mutta käytäntö on myös huomattavasti lisännyt asentoperäisen, ei-synostoottisen vinokalloisuuden esiintyvyyttä; tuoreen tutkimustiedon mukaan jopa lähes joka toisella imeväisellä on nähtävissä jonkinasteista asentovinokalloisuutta 7–12 viikon iässä. Etenkin USA:ssa ja muutamissa Keski-Euroopan maissa vaikea-asteista asentovinokalloisuutta hoidetaan aktiivisesti kypäräortoosein, mutta samanaikaisesti tietämys tilan luonnollisesta kulusta on vähäistä. Vaikka riskitekijöitä tunnetaan ja ehkäiseviä toimenpiteitä usein suositellaan, ei niiden tehosta ole juuri näyttöä. Nykyään 3D-pintakuvantamista käytetään usein vinokalloisten imeväisten seurannassa, mutta epäsymmetrian mittaamiseen käytettyjen muuttujien osuvuudesta ei ole tietoa. Tämän tutkimuksen tarkoituksena oli selvittää vastasyntyneiden vanhemmille annettavan vauvan käsittelyohjeistuksen vaikutusta asentovinokalloisuuden ilmaantuvuuteen satunnaistetussa, kontrolloidussa asetelmassa. Lisäksi pitkäaikaisseurannassa kartoitettiin asentovinokalloisuuden luonnollista kulkua ja ennusteeseen vaikuttavia tekijöitä suomalaisilla imeväisillä. Tutkimuksessa myös analysoitiin ja vertailtiin 3D-kuvista laskettavien epäsymmetriaa mittaavien muuttujien diagnostista osuvuutta. Käsittelyohjeita saaneiden lapsilla oli 3 kuukauden iässä merkittävästi vähemmän asentovinokalloisuutta ja kalloasymmetria oli lievempää kuin verrokkiryhmässä. Asentovinokalloisuuden esiintyvyys oli korkeimmillaan juuri 3 kuukauden iässä, jonka jälkeen merkittävää spontaania palautumista oli havaittavissa koko 12 kuukauden ikään jatkuneen seurannan ajan. Vastasyntyneillä nähty kalloasymmetria oli puolestaan ohimenevää, eikä myöskään vastasyntyneenä dokumentoitu kaulan liikerajoitus lisännyt myöhemmän vinokalloisuuden riskiä, vaan vinokalloisilla usein tavattava torticollis (kierokaula) näytti kehittyvän ensimmäisten elinviikkojen aikana yhdessä vinokalloisuuden kanssa. 3 kuukauden iässä havaittu imeväisen halu pitää päätään aina samaan suuntaan käännettynä oli yhteydessä kalloasymmetrian huonompaan spontaaniin palautumiseen. Tutkituista epäsymmetriaa mittaavista muuttujista OCLR erotteli vinokalloiset parhaiten. Yhteenvetona voidaan todeta, että ennaltaehkäisevä ohjeistus voisi vähentää vinokalloisuutta ja siitä aiheutuvia hoitokuluja kustannustehokkaasti, mutta vinokalloisuudelta on lupa odottaa myös merkittävää spontaania palautumista. Tutkimuksessa määritellyillä epäsymmetriaa mittaavien muuttujien raja-arvoilla on käyttöä sekä diagnostiikan että hoidon tavoitteiden määrittelemisen saroilla

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Nilsson, Kjell G. "Kinematics and fixation of total knee arthroplasties : a clinical, radiographic, scintimetric, and roentgen stereophotogrammetric evaluation." Doctoral thesis, Umeå universitet, Ortopedi, 1992. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100552.

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Aseptic loosening of the tibial component is an important cause of failure after total knee arthroplasty. Bone destruction often claimed to be caused by the cement makes the revision difficult. In order to treat younger patients, uncemented fixation has been introduced, but the etiology to loosening is multifactorial and only partly known. Early detection of implant migration facilitates research in this field but is difficult using conventional techniques. In this study modified versions of roentgen stereophotogrammetric analysis (RSA) were developed to obtain accurate and standardized evaluations facilitating comparison between prosthetic designs. The method was used to record the efficacy of cemented and uncemented fixation of different designs of the tibial component, to determine the accuracy of scintimetry in the detection of early aseptic loosening, and to analyse the in vivo kinematics of knee arthroplasties with different design and stability between the joint surfaces. Forty-three arthroplasties with comparatively high inherent stability of the joint surfaces were randomized to cemented or uncemented fixation of the tibial component. In all groups micromovements were rather large, but with no differences between the cemented and uncemented components. The preoperative diagnosis (arthrosis OA, n=25; rheumatoid arthritis RA, n=18) did not influence the magnitude of micromotion. 20 arthroplasties with the same design as above but equipped with an intramedullary stem, were randomized to cemented or uncemented fixation in patients with RA. Cement improved the fixation. Uncemented stemmed components displayed micromovements seemingly larger than unstemmed ones. 34 arthroplasties with an unconstrained design of the joint area and fixed to the tibia with four pegs were randomized to cemented or uncemented fixation in patients with OA. When used uncemented 4 screws were added. Compared with previously investigated designs small micromotions were recorded, and especially in the cemented cases. Uncemented components with thin polyethylene inserts displayed larger initial micromotions. The preoperative deformity influenced the direction of the micromotion. 33 knees were followed prospectively with RSA and scintimetry to evaluate any correlation between these methods. Low activity under the tibial component at 2 years implied prosthetic stability, whereas high activity indicated instability or high bone remodelling caused by the preoperative malalignment. The in vivo kinematics in three different designs of knee arthroplasties were analyzed during active flexion and extension without weight-bearing. Each type of prosthesis displayed design-specific abnormalities when compared with a normal material. Pronounced posterior tibial translations were recorded during flexion regardless whether the posterior cruciate ligament had been sacrificed or not. Data from the kinematic and the fixation studies suggest that movements restricted by the design of the joint area are transmitted to the bony interface with design-specific micromotions as the result. Analysis of knee joint kinematics during extension and weight-bearing revealed small alterations compared with non-weight-bearing. Evaluation of the three-dimensional movements in terms of helical axis rotations and translations confirmed the constrained or unconstrained in vivo behaviour of the designs under study. This analysis also facilitated the interpretation of the kinematic behaviour of the prosthetic knees and may be of value in the evaluation of new designs. Diss. (sammanfattning) Umeå : Umeå universitet, 1992, härtill 7 uppsatser. digitalisering@umu

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30

Vuollo, V. (Ville). "3D imaging and nonparametric function estimation methods for analysis of infant cranial shape and detection of twin zygosity." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526218557.

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Abstract The use of 3D imaging of craniofacial soft tissue has increased in medical science, and imaging technology has been developed greatly in recent years. 3D models are quite accurate and with imaging devices based on stereophotogrammetry, capturing the data is a quick and easy operation for the subject. However, analyzing 3D models of the face or head can be challenging and there is a growing need for efficient quantitative methods. In this thesis, new mathematical methods and tools for measuring craniofacial structures are developed. The thesis is divided into three parts. In the first part, facial 3D data of Lithuanian twins are used for the determination of zygosity. Statistical pattern recognition methodology is used for classification and the results are compared with DNA testing. In the second part of the thesis, the distribution of surface normal vector directions of a 3D infant head model is used to analyze skull deformation. The level of flatness and asymmetry are quantified by functionals of the kernel density estimate of the normal vector directions. Using 3D models from infants at the age of three months and clinical ratings made by experts, this novel method is compared with some previously suggested approaches. The method is also applied to clinical longitudinal research in which 3D images from three different time points are analyzed to find the course of positional cranial deformation and associated risk factors. The final part of the thesis introduces a novel statistical scale space method, SphereSiZer, for exploring the structures of a probability density function defined on the unit sphere. The tools developed in the second part are used for the implementation of SphereSiZer. In SphereSiZer, the scale-dependent features of the density are visualized by projecting the statistically significant gradients onto a planar contour plot of the density function. The method is tested by analyzing samples of surface unit normal vector data of an infant head as well as data from generated simulated spherical densities. The results and examples of the study show that the proposed novel methods perform well. The methods can be extended and developed in further studies. Cranial and facial 3D models will offer many opportunities for the development of new and sophisticated analytical methods in the future Tiivistelmä Pään ja kasvojen pehmytkudoksen 3D-kuvantaminen on yleistynyt lääketieteessä, ja siihen tarvittava teknologia on kehittynyt huomattavasti viime vuosina. 3D-mallit ovat melko tarkkoja, ja kuvaus stereofotogrammetriaan perustuvalla laitteella on nopea ja helppo tilanne kuvattavalle. Kasvojen ja pään 3D-mallien analysointi voi kuitenkin olla haastavaa, ja tarve tehokkaille kvantitatiivisille menetelmille on kasvanut. Tässä väitöskirjassa kehitetään uusia matemaattisia kraniofakiaalisten rakenteiden mittausmenetelmiä ja -työkaluja. Työ on jaettu kolmeen osaan. Ensimmäisessä osassa pyritään määrittämään liettualaisten kaksosten tsygositeetti kasvojen 3D-datan perusteella. Luokituksessa hyödynnetään tilastollista hahmontunnistusta, ja tuloksia verrataan DNA-testituloksiin. Toisessa osassa analysoidaan pään epämuodostumia imeväisikäisten päiden 3D-kuvista laskettujen pintanormaalivektorien suuntiin perustuvan jakauman avulla. Tasaisuuden ja epäsymmetrian määrää mitataan normaalivektorien suuntakulmien ydinestimaatin funktionaalien avulla. Kehitettyä menetelmää verrataan joihinkin aiemmin ehdotettuihin lähestymistapoihin mittaamalla kolmen kuukauden ikäisten imeväisten 3D-malleja ja tarkastelemalla asiantuntijoiden tekemiä kliinisiä pisteytyksiä. Menetelmää sovelletaan myös kliiniseen pitkittäistutkimukseen, jossa tutkitaan pään epämuodostumien ja niihin liittyvien riskitekijöiden kehitystä kolmena eri ajankohtana otettujen 3D-kuvien perusteella. Viimeisessä osassa esitellään uusi tilastollinen skaala-avaruusmenetelmä SphereSiZer, jolla tutkitaan yksikköpallon tiheysfunktion rakenteita. Toisessa osassa kehitettyjä työkaluja sovelletaan SphereSiZerin toteutukseen. SphereSiZer-menetelmässä tiheysfunktion eri skaalojen piirteet visualisoidaan projisoimalla tilastollisesti merkitsevät gradientit tiheysfunktiota kuvaavalle isoviivakartalle. Menetelmää sovelletaan imeväisikäisen pään pintanormaalivektoridataan ja simuloituihin, pallotiheysfunktioihin perustuviin otoksiin. Tulosten ja esimerkkien perusteella väitöskirjassa esitetyt uudet menetelmät toimivat hyvin. Menetelmiä voidaan myös kehittää edelleen ja laajentaa jatkotutkimuksissa. Pään ja kasvojen 3D-mallit tarjoavat paljon mahdollisuuksia uusien ja laadukkaiden analyysityökalujen kehitykseen myöhemmissä tutkimuksissa

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31

Önsten, Ingemar. "Fixation of total hip components in rheumatoid arthritis and srthrosis a radiographic, roentgen stereophotogrammetric, densitometric and histomorphometric study /." Lund : Dept. of Orthopaedics, University of Lund, Malmö General Hospital, 1994. http://books.google.com/books?id=mGVsAAAAMAAJ.

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32

Gold, Brenda Joan. "A roentgen stereophotogrammetric analysis system for the measurement of subsidence of the femoral components in total hip arthroplasty." Thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/26276.

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33

Bonci, Tecla. "La reconstruction du mouvement du squelette : l'enjeu de l'artefact des tissus mous." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10056/document.

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Lors de l'analyse 3D du mouvement humain basée sur des marqueurs cutanés, la position des os ne peut être qu'indirectement estimée. Au cours d'une tâche, les déformations des tissus mous génèrent des déplacements des marqueurs par rapport à l'os : les artefacts de tissus mous (STA), entraînant des effets dévastateurs sur l'estimation de la position. La compensation des STA demeure une question ouverte. L'objectif de cette thèse est de contribuer à la solution de cette question cruciale. La modélisation des STA en utilisant des variables spécifiques mesurables est une condition préalable à son élimination. Un modèle corrigeant les trajectoires individuelles de marqueurs de la cuisse, calibré par des mesures directes des STA, est d'abord présenté. Les STA sont modélisés comme une combinaison linéaire des angles articulaires impliqués. Trois représentations des STA par une série de modes sont proposées : déplacements de marqueurs individuels, transformations géométriques de clusters de marqueurs (MCGT), et variations de forme de l'enveloppe de peau. Le MCGT permet de dissocier les composantes rigides et non rigides. Il a été démontré que seule la composante rigide affecte la cinématique articulaire. Un modèle de cette composante est alors défini pour les clusters cuisse et jambe. Un compromis acceptable entre la correction des STA et le nombre de paramètres a ainsi été obtenu. Les principales applications sont de générer une simulation réaliste des STA ; et surtout, en se concentrant sur la composante rigide, le modèle permet une reconstruction satisfaisante des STA avec moins de paramètres, ce qui facilite son incorporation dans un algorithme d'estimation de la position osseuse In 3D human movement analysis performed using stereophotogrammetry and skin markers, bone pose can be only indirectly estimated. During a task, soft tissue deformations make the markers move with respect to the underlying bone generating soft tissue artefacts (STA), causing devastating effects on pose estimation and its compensation remains an open issue. The thesis’ aim was to contribute to the solution of this crucial issue. Modelling STA using measurable trial-specific variables is a prerequisite for its removal from marker trajectories. Two STA model architectures are proposed. A thigh marker-level model is first presented. STA was modeled as a linear combination of joint angles involved in the task. The model was calibrated with direct STA measures. The considerable number of model parameters led to defining STA approximations. Three definitions were proposed to represent STA as series of modes : individual marker displacements, marker-cluster geometrical transformations (MCGT), and skin envelope shape variations. Modes were selected using two criteria : modal energy and selecting them a priori. The MCGT allows to select either rigid or non-rigid components. It was also demonstrated that only the rigid component affects joint kinematics. A model of thigh and shank rigid component at cluster-level was then defined. An acceptable trade-off between STA compensation and number of parameters was obtained. These results lead to two main potential applications : generate realistic STAs for simulation

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34

Jonsson, Håkan. "Knee joint laxity and kinematics after anterior cruciate ligament rupture : roentgen stereophotogrammetric and clinical evaluation before and after treatment." Doctoral thesis, Umeå universitet, Ortopedi, 1993. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100568.

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Rupture of the anterior cruciate ligament (ACL) increases anterior-posterior (AP) laxity. The treatment aims to reduce or teach the patient to control this instability. Altered kinematics due to absent ligament function may result in knee arthrosis. This study evaluated the clinical and functional results of reconstructive surgery. Roentgen stereophotogrammetry (RSA) was used to analyse the stabilising effect of knee braces, reconstructive surgery and the kinematics of the knee with and without weight-bearing. The stability of the knees were assessed in 86 patients with ACL injuries before and/or after reconstructive surgery with the RSA technique and with the KT-1000 arthrometer The KT- 1000 (89 N) recorded smaller side to side differences than the RSA set-up without any correlation between the methods. The effect of three different braces on the AP and rotatory laxity was studied on patients with ACL injuries. The ECKO and the modified Lenox Hill reduced the instability with about one third. The SKB had no significant effect. None of the braces decreased the internal rotatory laxity but the Lenox Hill reduced the external rotatory laxity. Thirty-two patients with old ACL tears were treated with surgical reconstruction using the over the top technique (OTT) with or without augmentation. A small reduction in AP laxity was observed at the 6 month follow-up, The AP laxity was almost the same two years after as before surgery. No correlation was observed between the stability and knee function. Fifty-four patients with old unilateral anterior cruciate ligament injuries were randomised either to the over the top (OTT) or the isometric femoral tunnel position (ISO) at ACL reconstructive surgery. Seven of 24 (ISO) and 9 of 25 (OTT) had "normal" laxity two years after surgery. The patients operated with the ISO technique did not have better subjective knee function, muscle strength, functional performance or knee stability than patients operated with the OTT technique. The knee kinematics in patients with chronic unilateral ACL ruptures were examined during active extension in the supine position (13 patients) and during extension and weight-bearing (13 patients). The tibia displaced at an average 1.9 mm more anteriorly and 0.8 mm distally in the injured than in the intact knees during active extension. During extension and weightbearing the tibia was about 2 mm more posteriorly positioned than in the intact knee. The ACL rupture did not affect tibial rotations. Conclusions: The RSA recorded larger side to side differences in ACL injured and reconstructed patients than the KT-1000 arthrometer. Some knee braces are able to reduce AP laxity in ACL injured knees. No correlation was observed after surgery between knee laxity and functional scoring or tests. ACL reconstructions with isometric graft position on the femoral side did not offer any advantages compared to the over the top placement. Altered knee kinematics in the ACL injured knees were observed during knee extension with and without weight-bearing. Diss. (sammanfattning) Umeå : Umeå universitet, 1993, härtill 6 uppsatser digitalisering@umu

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35

Sabino, Danilo Damasceno. "Development of a 3D multi-camera measurement system based on image stitching techniques applied for dynamic measurements of large structures." Ilha Solteira, 2018. http://hdl.handle.net/11449/157103.

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Orientador: João Antonio Pereira Resumo: O objetivo específico deste trabalho é estender as capacidades da técnica de rastreamento de pontos em 3 dimensões (three-dimensional point tracking – 3DPT) para identificar as características dinâmicas de estruturas grandes e complexas, tais como pás de turbina eólica. Um sistema multi-camera (composto de múltiplos sistemas de estéreo visão calibrados independentemente) é desenvolvido para obter alta resolução espacial de pontos discretos a partir de medidas de deslocamento sobre grandes áreas. Uma proposta de técnica de costura é apresentada e empregada para executar o alinhamento de duas nuvens de pontos, obtidas com a técnica 3DPT, de uma estrutura sob excitação dinâmica. Três diferentes algoritmos de registro de nuvens de pontos são propostos para executar a junção das nuvens de pontos de cada sistema estéreo, análise de componentes principais (Principal Component Analysis - PCA), decomposição de valores singulares (Singular value Decomposition - SVD) e ponto mais próximo iterativo (Iterative Closest Point - ICP). Além disso, análise modal operacional em conjunto com o sistema de medição multi-camera e as técnicas de registro de nuvens de pontos são usadas para determinar a viabilidade de usar medidas ópticas (e.g. three-dimensional point tracking – 3DPT) para estimar os parâmetros modais de uma pá de gerador eólico comparando seus resultados com técnicas de medição mais convencionais. Abstract: The specific objective of this research is to extend the capabilities of three-dimensional (3D) Point Tracking (PT) to identify the dynamic characteristics of large and complex structures, such as utility-scale wind turbine blades. A multi-camera system (composed of multiple independently calibrated stereovision systems) is developed to obtain high spatial resolution of discrete points from displacement measurement over very large areas. A proposal of stitching techniques is presented and employed to perform the alignment of two point clouds, obtained with 3DPT measurement, of a structure under dynamic excitation. The point cloud registration techniques are exploited as a technique for dynamic measuring (displacement) of large structures with high spatial resolution of the model. Three different image registration algorithms are proposed to perform the junction of the points clouds of each stereo system, Principal Component Analysis (PCA), Singular value Decomposition (SVD) and Iterative Closest Point (ICP). Furthermore, operational modal analysis in conjunction with the multi-camera measurement system and registration techniques are used to determine the feasibility of using optical measurements (e.g. three-dimensional point tracking (3DPT)) to estimate the modal parameters of a utility-scale wind turbine blade by comparing with traditional techniques. Doutor

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36

Casanova, Pascal. "Bétons renforcés de fibres métalliques : Du matériau à la structure. Etude expérimentale et analyse du comportement de poutres soumises à la flexion et à l'effort tranchant." Phd thesis, Marne-la-vallée, ENPC, 1995. http://www.theses.fr/1995ENPC9517.

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Les bétons renforcés de fibres métalliques (BFM) connaissent, à ce jour, peu d'applications dans le domaine des éléments de structure. Cet état de fait est, en grande partie, imputable à l'absence de méthodes de calcul, donc à la difficulté d'apprécier l'apport structural de ces matériaux. Le travail présenté ici a pour but de combler cette lacune dans le cas des poutres. Pour répondre au problème posé, l’étude s’appuie sur des essais de structures réalisés, pour d’une part, étudier les mécanismes de rupture et, d’autre part, de valider les modèles élaborés. Des essais sont ainsi effectués en flexion simple et à l’effort tranchant. Une méthode performante a été utilisée pour le suivi global de la fissuration : la stéréophotogrammétrie. Elle a clairement montré une localisation précoce de la fissuration et l’apparition d’un mécanisme de rupture par blocs. Ces essais mettent en évidence que la caractéristique fondamentale des BFM est leur comportement postfissuration en traction. Un essai de traction uniaxiale sur éprouvette entaillée est utilisé, et développé, pour mesurer la capacité des fibres à reprendre un effort à travers une fissure. Les éprouvettes sont carottées, dans la direction des contraintes principales de traction, pour tenir compte de l’anisotropie de répartition des fibres induite par la mise en œuvre. Une modélisation a été développée à partir des mécanismes étudiés et en prenant comme donnée matériau les résultats de l’essai de traction. Une première famille de modèles consiste à postuler un mécanisme de rupture, puis à calculer l’équilibre de la structure, en fonction de l’ouverture de la fissure, à partir de la relation expérimentale obtenue en traction. Des résultats très satisfaisants ont été obtenus en flexion. En ce qui concerne l’effort tranchant, l’apport des fibres est correctement appréhendé et une relation d’équivalence a été obtenue avec les armatures transversales utilisée habituellement. La prise en compte de l’évolution, avec l’ouverture de fissure, de la contrainte résiduelle postfissuration s’avère indispensable pour retrouver les effets d’échelle observés. L’utilisation d’une méthode en partie empirique pour l’effort tranchant est liée aux limites des modèles simples. Afin de s’affranchir de cette limite et d’étendre la modélisation à des cas complexes, il est apparu nécessaire d’utiliser une modélisation par éléments finis. Un modèle continu (plasticité) et un modèle discret (modèle probabiliste de fissuration) ont été utilisés. En conclusion, il a été mené une étude complète du matériau à la structure. Cette étude, à la fois expérimentale et théorique, a permis de définir des méthodes de calcul qui, couplées à une démarche globale de la composition à la caractérisation, en passant par la fabrication, permettent d'optimiser la conception des éléments de structure en BFM Steel fibre reinforced concrete (SFRC) are rarely used in truly structural applications. This fact is mainly due to the lack of design tools, and consequently to the difficulty in quantifying the structural part due to these materials. The objective of this work is to give an answer to this matter in the case of beams. The structural performed tests have two goals : firstly, to study the failure mechanisms and, secondly, to validate the models developed in this work. Test are thus carried out in bending and shear. A global investigation tool, stereophotogrammetry, is used to study the cracking pattern : it shows clearly an early crack localization and the onset of a block mechanism which leads to a block type failure. These tests point out that the main mechanical characteristic of SFRC is their post cracking behaviour in tension. A uniaxial tension test on notched specimens is used, and developed, to measure a load – crack opening relationship. Specimens are cored, in the direction of the main load, to take into account the anisotropy due to concreting. A first type of model consists in postulating a failure mechanism, then in calculating the equilibrium of the structure, as a function of the crack opening, starting from the experimental relationship obtained in tension. Modelling of bending leads to good results. Concerning shear behaviour, the fibre part is correctly calculated and an equivalence relationship with classical stirrups is achieved. To take into account the observed scale effects, it is necessary to consider the evolution, with the crack opening, of the residual strength in tension. An empirical relationship is necessary to quantify the structural part of shear resistance. This illustrates the limits of simple models. Therefore, it seems necessary to use finite elements to model structures submitted to complex loading. A continuous approach (plasticity) and a discrete one (the LCPC’s probabilistic model) are used. To conclude, a complete study was carried out from the material to the structure. This study, experimental and theoretical, presents methods of analysis that, coupled with a global procedure from mix design to mechanical characterization, allow to optimize the desing of SFRC structural elements

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Roger, Vincent. "Etude expérimentale et théorique de la localisation des déformations dans les matériaux granulaires en condition isochore." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE10022.

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La localisation des deformations en bande de cisaillement dans les materiaux granulaires satures denses en condition isochore est abordee suivant les approches experimentale et theorique. L'etude experimentale est menee en deformation plane sur l'appareil biaxial developpe a grenoble, et realisee sur le sable d'hostun rf. En condition non drainee sur materiau dense, on observe la manifestation du phenomene de cavitation au cours de la sollicitation. La relation entre la cavitation et la localisation des deformations en bande de cisaillement est precisee a travers l'evolution des parametres suivants : le niveau de pression interstitielle initiale, la vitesse de sollicitation, la taille des grains, et la viscosite du fluide interstitiel. En complement, des essais speciaux sont realises : essais d'injection sur l'appareil biaxial ; et essais isochores sur materiau sec en deformation plane sur une presse tridimensionnelle vraie. Enfin, une analyse du champ de deformation des echantillons en utilisant la stereophotogrammetrie de faux relief est presentee, ainsi qu'une analyse microstructurelle de lames minces sur un certain nombre d'echantillons. L'etude theorique s'insere dans le cadre du developpement de la famille de lois non lineaires cloe. Deux points sont abordes dans cette etude. Le premier point consiste a etendre au non draine le critere de localisation defini en condition drainee pour cette famille de lois. Le second point consiste a developper un modele heuristique, le modele minicloe - drucker-prager. Ce modele a ete developpe afin d'obtenir des resultats fondamentaux sur le critere de bifurcation en bande de cisaillement pour les lois cloe. Une etude parametrique de ce modele permet de comparer le seuil de perte d'unicite d'un probleme formule en vitesse, i. E. De perte de positivite du travail du second ordre, et le seuil de localisation dans l'espace des contraintes.

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Su, Chia-ping, and 蘇嘉平. "Wave measurement by Stereophotogrammetry – a primary study." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/09928001646283657947.

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碩士 國立成功大學 水利及海洋工程學系碩博士班 97 In this study, the camera in wave three-dimensional photography, image processing techniques applied analysis of wave field, its process consists of imaging the internal calibration, external calibration, image matching and three-dimensional image reconstruction. In which three-dimensional image reconstruction of the image matching is to study the core of this paper, Epipolar Geometry and Normalized Cross Correlation to image matching method to improve the efficiency of image matching. To reduce the image matching error, this paper, three cameras, and developing a nuclear program review. The results showed that the introduction of the third camera can seize the nuclear image matching accuracy and avoid a match with only two images of the phenomenon of miscarriage of justice. The findings of this study, to 23 × 23 pixels as the matching window size is the best result. This paper designs two kinds of tests of three-dimensional photographic technique, the measurement accuracy, the first is the flat position of the certification, equipped with 40-centimeter square tiles each of the room . The second is a high degree of measurement of the verification, using a static wave plate. Three-dimensional image reconstruction of the test results regardless of plane (ranging from 3 to 6 meters) and in wave height (3 cm) on the errors are less than 5%, studies have shown that cameras and the distance between the target and the camera between the camera Spacing distances affect the results of image reconstruction accuracy factor. This study also determined that the spacing of the camera does not need an unlimited extension of the distance between the camera and the shooting distance than the value of a balance, its high degree of accuracy will tend to be value.

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ANCILLAO, ANDREA. "Stereophotogrammetry in human movement analysis: novel methods for the quality assurance, biomechanical analysis and clinical interpretation of gait analysis." Doctoral thesis, 2017. http://hdl.handle.net/11573/938022.

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The study of movement has always fascinated artists, photographers and researchers. Across the years, several attempts to capture, freeze, study and reproduce motion were made. Nowadays, motion capture plays an important role within many fields, from graphical animation, filmmaking, virtual reality, till medicine. In fact, movement analysis allows to measure kinematic and kinetic performance of the human body. The quantitative data obtained from measurements may support the diagnosis and treatment of many pathologies, allowing to take clinical decisions and supporting the follow-up of treatments or rehabilitation. This approach is nowadays named evidence based medicine. In this work, motion capture techniques and advanced signal processing techniques were exploited in order to: (i) develop a protocol for the validation and quality assurance of the clinical strength measurements, (ii) develop an algorithm for clinical gait analysis data interpretation and identification of pathological patterns, and (iii) design user-friendly software tools to help clinicians using the novel data processing algorithms and reporting the results of measurements. This work was divided into three sections: Part 1 contains a survey about the history of motion analysis and a review of the earliest experiments in biomechanics. The review covered the first historical attempts, that were mainly based on photography, till the state-of-the-art technology used today, i.e. the optoelectronic system. The working principle of optoelectronic system was reviewed as well as its applications and modern setups in the clinical practice. Some modern functional evaluation protocols, aimed to the quantitative evaluation of physical performance and clinical diagnosis of motor disorders, were also reviewed. Special attention was paid to the most common motion analysis exam that is nowadays worldwide standardized, i.e. the Gait Analysis. Examples of Gait Analysis studies on subjects with pathology and follow-up were reviewed. Part 2 concerns the design of an experimental setup, involving motion analysis, for the quality assurance of clinical strength measurements. Measurements of force are popular in the clinical practice as they allow to evaluate the muscle weakness, health status of patients and the effects of therapies. A variety of protocols was proposed to conduct such measurements, implying the acquisition of forces, angles and angular velocities when the maximum voluntary force is exerted. Hand held dynamometry (HHD), based on single component load cell, was extensively used in clinical practice; however, several shortcomings were identified. The most relevant were related to the operator’s ability. This work was aimed to investigate the inherent inaccuracy sources in knee strength measurements when are conducted by a single component load cell. The analysis was conducted by gathering the outputs of a compact six-component load cell, comparable in dimension and mass to clinical HHDs, and an optoelectronic system. Quality of measurements was investigated in terms of quantifying, by an ad-hoc metrics, the effects induced in the overall inaccuracy by: (i) the operator’s ability to place and to hold still the HHD and (ii) ignoring the transversal components of the force exchanged between the patient and the experimenter. The main finding was that the use of a single component HHD induced an overall inaccuracy of 5% in the strength measurements, when operated by a trained clinician and angular misplacements are kept within the values found in this work (≤15°) and with a knee ROM ≤ 22°. Even if the measurement outputs were reliable and accurate enough for both knee flexion and extension, extension trials were the most critical due to the higher force exerted, i.e. 249.4±27.3 N vs. 146.4±23.9 N of knee flexion. The most relevant source of inaccuracy was identified in the angular displacement of HHD on the horizontal plane. A dedicated software, with graphical user interface, was designed and implemented. The purposes of this software were to: (i) speed up data processing, (ii) allow user to select the proper processing workflow, and (iii) provide clinicians with a tool for quick data processing and reporting. Part 3 concerns the research study about gait analysis on subjects with pathology. Gait analysis is often used for the assessment of the gait abilities in children with cerebral palsy and to quantify improvements/variations after a treatment. To simplify GA interpretation and to quantify deviation from normality, some synthetic descriptors were developed in literature, such as the Movement Analysis Profile (MAP) and the Linear Fit Method (LFM). The aims of this work were: (i) to use synthetic descriptors in order to quantify gait variations in subjects with Cerebral Palsy that underwent surgery involving bone repositioning and muscle/tendon lengthening at the level of the femur and hamstring group (SEMLS); (ii) test the effectiveness of a recently proposed index, i.e. the LFM, on such patients; (iii) design and implement a novel index that may overcome the limitations of the previous methods. Gait Analysis exams of 10 children with Cerebral Palsy, pre and post treatment, were collected. Data were analysed by means of MAP and LFM indices. To overcome the limitations observed for the methods, another index was designed as a modified version of the MAP, namely the OC-MAP. It took into account the effect on deviation due to offset and allowed to compute the deviation from normality on tracks purified by the offset. An overall improvement of the gait pattern was observed for most of the subjects after surgery. The highest effect was observed for the knee flexion/extension angle. Patients who had initial high deviations also had the largest improvements. Worsening in the kinematics of the pelvis could be explained as a consequence of SEML involving a lengthening of hamstring group. Pre-post differences were higher than the Minimally Clinical Important Difference for all parameters, except hip flexion. An improvement towards normality was observed for all the parameters, with exception of pelvic tilt for which a worsening was observed. LFM provided results similar to OC-MAP offset analysis but could not be considered reliable due to intrinsic limitations. As offset in gait features played an important role in gait deviation, OC-MAP synthetic analysis is recommended to study gait pattern of subjects with Cerebral Palsy. A dedicated software, with graphical user interface, was designed and implemented. The purpose of this software was to compute the synthetic descriptors on a large amount of data, to speedup data processing and to provide clinicians with a quick access to the results

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Birkner, Luisa. "Vergleichende Untersuchungen zur Wiedergabegenauigkeit optoelektronischer berührungsloser und plastischer Abformungen weicher Gesichtsstrukturen: Dissertation zur Erlangung des akademischen Grades Dr. med. dent. an der Medizinischen Fakultät der Universität Leipzig." Doctoral thesis, 2013. https://ul.qucosa.de/id/qucosa%3A12402.

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Vergleichende Untersuchungen zur Wiedergabegenauigkeit optoelektronischer berührungsloser und plastischer Abformungen weicher Gesichtsstrukturen Universität Leipzig, Dissertation Problemstellung: Deformation der fazialen Weichgewebe bei liegenden Patienten, hervorgerufen durch schwerkraft- und materialgewichtabhängige Einflüsse der bei konventionellen Abformmethoden verwendeten Materialien Hydrokolloiden und Elas- tomere. Ziel: Vergleich der Wiedergabegenauigkeit weicher Gesichtsstrukturen bei konven- tionellen plastischen Abformmethoden und einem optischen, mechanischen berüh- rungsfreien dreidimensionalen fotorealistischen Modell. Material und Methode: Konventionelle Abformung bei 20 Probanden mit Hydrokolloid und Elastomer sowie ein optischer Gesichtsscan vom Mittelgesicht. Studienaufbau: Digitali- sieren der Gipsmodelle und Auswertung aller STL-Datensätze zum Vergleich zwischen plastischen und optoelektronischen Abformungen sowie die Evaluation der vorhandenen Abweichungen in 34 konstruierten Punkten. Statistik: Testen auf Normalverteilung und Varianzengleichheit zum Prüfen der Signifikanz mittels Zweistichproben-t-Test und Wilcoxon-Rangsummen-Test. Ergebnisse: Der allgemeiner Abformfehler zwischen optischem Scan und konven- tionellen Abformungen liegt bei 1,19 mm ± 0,32 mm mit Variationen bei den Ma- terialien Alginat 1,02 mm ± 0,24 mm und Silikon 1,36 mm ± 0,31 mm. Signifikante Unterschiede zwischen den Abformmaterialien zeigen sich in 6 von 34 Messpunkten (p < 0,05). Alginat weist tendentiell die besseren Ergebnisse auf und ruft weniger Weichgewebsveränderung hervor. Die beschriebenen Differenzen entstehen durch die Deformation der Weichgewebe bei der Gesichtsabformung. Bei den Punkten ohne statistische Signifikanz ist die Abformtechnik als sehr präzise zu betrachten. In gut skelettal-unterstützten Regionen zeigt Silikon in einigen Messpunkten geringere Abweichungen. Schlussfolgerung: Die Auswahl des Abformmaterials sollte in Abhängigkeit von der Ausgangssituation gewählt werden. Trotz der modifizierten Abformtechnik zeigen die Ergebnisse einen deutlichen Unterschied zwischen digital erfasstem dreidimensionalem Gesichtsscan und konventionellen Abformmethoden. Den optischen Systemen ist derzeit der Vorzug zu geben. Die Vorteile sind hinsichtlich noninvasiver, iterierender Aufnahmen, genauerer und effektiverer Analyse sowie CAD/CAM-Herstellung von Epithesen aus biokompatiblen Werkstoffen beachtlich.:1. Einleitung und Zielstellung 2. Literatur 2.1 Geschichtliches 2.2 Konventionelle Methoden zur Erfassung der dreidimensionalen Gesichtsmorphologie 2.2.1 Abformwerkstoffe 2.2.2 Modellmaterial Gips 2.2.3 Einflussfaktoren auf konventionelle Gesichtsabformungen 2.3 Kontaktfreie Verfahren der Tiefenbilderzeugung zur Erfassung der dreidimensionalen Gesichtsmorphologie 2.3.1 Reflektive Verfahren 2.3.2 Transmissive Verfahren 2.4 Einführung in die praktische Herstellung von Epithesen mittels Computer Aided Design/Computer Aided Manufacturing (CAD/CAM-Techniken) und Rapid Prototyping 2.5 Synopsis der Vor- und Nachteile konventioneller Abformmethoden und optischer Methoden zur dreidimensionalen Oberflächenerfassung 3. Material und Methode 3.1 Versuchsaufbau und Prinzipübersicht 3.2 Konventionelle Abformmethodik 3.2.1 Herstellung eines individuellen Löffels 3.2.2 Gesichtsabformung mit Alginat 3.2.3 Gesichtsabformung mit Silikon 3.2.4 Modellherstellung aus Gips 3.3 Optische Methoden 3.3.1 Dreidimensionale Erfassung der Modelle mit Atos 3.3.2 Dreidimensionale Erfassung des Gesichtes mit Canfield 3.4 Auswertung der STL-Datensätze 3.4.1 Erstellen von überlagerten Bildern 3.4.2 Auswertung der Modelle mit Hilfe von festgelegten Bezugspunkten 3.5 Statistik 4. Ergebnisse 4.1 Deskriptive Darstellung der Ergebnisse der Norm zwischen dem opto- elektronischen berührungslosen dreidimensionalen Gesichtsscan und der plastischen Abformmethode mit dem Material Alginat 4.2 Deskriptive Darstellung der Ergebnisse der Norm zwischen dem opto- elektronischen berührungslosen dreidimensionalen Gesichtsscan und der plastischen Abformmethode mit dem Material Silikon 4.3 Synopsis der Abweichungen konventioneller Abformmethoden gegen- über optoelektronischen Gesichtsscans 4.4 Alters- und geschlechtsspezifische Einflüsse auf die Weichgewebs- schichtstärken bei konventionellen Abformungen 4.5 Statistische Verfahren zum Testen von Hypothesen 5. Diskussion 5.1 Diskussion der Problemstellung 5.2 Diskussion der Zielsetzung 5.3 Diskussion von Material und Methode 5.3.1 Festlegen des Studiendesigns 5.3.2 Herstellung des Löffels 5.3.3 Verwendete Abformmaterialien 5.3.4 Methodik 5.4 Diskussion der Ergebnisse 6. Zusammenfassung der Arbeit 7. Glossar 8. Literaturverzeichnis 9. Verzeichnis der Abbildungen und Tabellen 10. Anhang

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Tsai, Tsung-Yuan, and 蔡宗遠. "Development of a 3D Fluoroscopy Method and its Integration with Stereophotogrammetry to Study the Effects of Soft Tissue Artifacts on the Calculated Mechanical Variables of the Knee During Functional Activities." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/16552219252804844742.

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博士 臺灣大學 醫學工程學研究所 98 Accurate measurement of the three-dimensional (3D) rigid body and surface kinematics of the natural and implanted knee is essential for many clinical applications. Skin marker-based stereophotogrammetry has been widely used in the in vivo, non-invasive measurement of 3D joint kinematics. However, the measured poses of body segments are subject to errors called soft tissue artifacts (STA). Existing techniques are limited either in their accuracy or lack of more realistic experimental evaluation of the measurement errors. The purposes of the study were to develop a volumetric model-based 2D-to-3D registration method, called the weighted edge-matching score (WEMS) method, for measuring accurate natural and implanted knee kinematics with single-plane fluoroscopy; to assess the 3D movement of skin markers relative to the underlying bones in normal subjects during functional activities; to access the effects of STA on the calculated joint variables at the knee in normal subjects during stair-ascent (SA); to quantify the STA and their effects on the calculated variables of the knee in patients with total knee replacements (TKR) during sit-to-stand (STS); and to validate the performance and effectiveness of global optimization method (GOM) with an appropriate kinematic model for compensating the STA for in vivo knee kinematics of normal, anterior cruciate ligament deficient (ACLD) and TKR subjects during functional activities. The precision of the WEMS method has been determined experimentally with cadaver knee and TKR. With the help of integrated 3D fluoroscopy method and stereophotogrammetry, considerable STA of normal and TKR subjects, during SA and STS respectively, were found and which led to significant differences of measured biomechanical variables of the knee. Compensating the effects of STA with GOM showed that the mean values of root mean squared error (RMSE) over all functional activities of all kinds of subjects were in the order of 3-6 mm for measurement of knee joint translations and about 3˚ for knee joint rotations. These findings suggested that GOM would be helpful for compensating STA in human motion analysis for basic research and clinical applications.

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Osborn, Jonathan E(Jonathan Edward). "Design and calibration of close-range stereophotogrammetric systems in biology and biomedicine." Thesis, 1995. https://eprints.utas.edu.au/21106/1/whole_OsbornJonathanEdward1995_thesis.pdf.

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This thesis discusses the design and calibration of close-range stereophotogrammetric systems in biology and biomedicine. Two applications of photogrammetry are described The first is the design and validation of a photogrammetric method of measuring the surface topography of the human cornea. The second encompasses three photogrammetric methods of measuring the aggregation behaviour of underwater animals. Some aspects of the designs have required new instrumentation, others have required further investigation of current techniques or the application of established technique to new circumstances. Two investigations that were a component of the design and calibration process are described in detail. One is an investigation of the accuracy of video tape as a recording medium in digital photogrammetry. The other is an investigation of the geometric reliability of an underwater stereocamera submerged in deep-water. The applications and investigations that are described serve to illustrate a cross section of current technology and methodology in biomedical and biological stereophotogrammetry. They involve both analogue and digital cameras, single media and multi-media environments, and conventional and unconventional data reduction methods. The thesis includes: i. a review of relevant analytical and digital stereophotogrammetric techniques; 11. a description of a new method of measuring the anterior surf ace topography of the human cornea and the design of a digital implementation of a corneal measurement system; 111. a description of three applications of photogrammetry in underwater animal behaviour research; iv. an investigation of the metric characteristics of one type of image recording medium; and v. an investigation of the calibration parameters of an underwater stereocamera. The applications described share three characteristics: i. they illustrate the operational restrictions that can impose on a photogrammetric solution; ii. they have required an investigation of some aspect of the photogrammetric process; and iii. they have required an understanding of the discipline of the end-user. In the light of these characteristics a common theme is developed. Namely the extent to which a photogrammetrist must recognise the objectives, methods, and constraints imposed by the user of photogrammetric data and the way in which that affects the photogrammetric solution.

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Kunz, Jessica. "Kopforthesentherapie bei Patienten mit lagerungsbedingtem Plagiozephalus: Einfluss von Alter und Schweregrad der Asymmetrie bei Therapiebeginn auf die Therapiedauer und das Therapieergebnis." Doctoral thesis, 2020. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-208446.

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Zur Kopforthesentherapie in der Behandlung von Säuglingen mit lagerungsbedingten Schädelasymmetrien gibt es bisher kaum Studien, die den optimalen Behandlungsbeginn unter Berücksichtigung der Ausprägung der Asymmetrie untersuchen. Ziel der vorliegenden Studie war es daher, den Einfluss des Alters und des Schweregrades der Asymmetrie bei Therapiebeginn auf die Therapiedauer und das Therapieergebnis zu analysieren. Hierzu wurden 144 Patienten mit lagerungsbedingtem Plagiozephalus untersucht, die mittels Kopforthese behandelt wurden. Es erfolgte eine Einteilung in drei Altersgruppen (Altersgruppe I: < 24 Wochen mit N = 38 Säuglingen / Altersgruppe II: ≥ 24 bis < 32 Wochen mit N = 79 Säuglingen / Altersgruppe III: ≥ 32 Wochen mit N = 27 Säuglingen) und je zwei Schweregrade (mild-to-moderate: 30°-CVA >3mm bis <12mm / moderate-to-severe: 30°-CVA ≥12mm). Anhand stereophotogrammetrischer Datensätze wurden das Ausmaß und die Reduktion der Asymmetrie in den verschiedenen Untergruppen sowie die Therapiedauer miteinander verglichen. Es zeigte sich, dass es in allen Altersgruppen zu einer signifikanten Reduktion der Asymmetrie kam, wobei sich dieser Effekt mit steigendem Alter verringerte. Ein Therapieerfolg (= CVAI <3,5%) wurde bei Patienten mit mild-to-moderate Asymmetrie in Altersgruppe I zu 83%, in Altersgruppe II zu 69% und in Altersgruppe III zu 40% erreicht. Bei Patienten mit einer schwerwiegenderen, moderate-to-severe Asymmetrie ergab sich eine symmetrische Kopfform zu 50% in Altersgruppe I, zu 30% in Altersgruppe II und nur zu 7% in Altersgruppe III. Die durchschnittliche Therapiedauer stieg von 18,6 Wochen in Altersgruppe I, 20,0 Wochen in Altersgruppe II und 25,3 Wochen in Altersgruppe III an. Das Alter bzw. der Schweregrad der Asymmetrie bei Behandlungsbeginn wurden durch die multiple Regressionsgleichung ins Verhältnis gesetzt. Dadurch kann zukünftig die zu erwartende Verbesserung der Asymmetrie durch eine Kopforthesentherapie abgeschätzt werden. Zusammenfassend kann somit festgestellt werden, dass das Alter bei Therapiebeginn sowie der Ausprägungsgrad einer lagerungsbedingten Asymmetrie einen entscheidenden Einfluss auf Dauer und Effektivität der Kopforthesentherapie haben. Die Erfolgsrate der Therapie ist maßgeblich von diesen beiden Einflussfaktoren abhängig. Die aufgestellte Regressionsgleichung ermöglicht eine Vorhersage der Reduktion einer lagerungsbedingten Schädelasymmetrie Background Only few studies investigating the optimal time point to start head orthosis therapy for deformational plagiocephaly (DP) take into account the severity of skull asymmetry. The present study performs a 3D-analysis of the effects of age and severity of asymmetry on the final outcome. Methods A total of 144 patients with DP treated by molding orthosis were examined and divided into three age groups (I: <24 weeks; II: ≥24 to <32 weeks; III: ≥32 weeks) and two severity levels (mild-to-moderate: 30°-CVA ≥3mm to ≤12mm; moderate-to-severe: 30°-CVA >12mm). The extent of the reduction of asymmetry was analyzed using 3D-stereophotogrammetry. Results Therapy with molding orthosis led to a significant reduction in asymmetry in all defined age groups. Efficacy of reduction decreased with increasing age. Successful treatment (=CVAI <3.5%) of patients with mild-to-moderate asymmetry was achieved in 83%, 69% and 40% (groups I, II and III), respectively, in 50%, 30% and 7% of patients with moderate-to-severe asymmetry. The average duration of treatment increased from 18.6 to 25.3 weeks (age groups I and III). Conclusion Age at the beginning of treatment as well as severity of asymmetry have a definite impact on the duration and effectiveness of molding orthosis therapy

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Linz, Christian. "Daten der ersten Kindervorsorgeuntersuchung (U1), Quantifizierung des einseitigen lagerungsbedingten Plagiocephalus und Evaluation der Therapie mit individueller Kopforthese mittels Sterophotogrammetrie." Doctoral thesis, 2013. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-77858.

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Zusammenfassung Ziel: Eine lagerungsbedingte einseitige Abflachung des Hinterkopfes aufgrund externer Kräfte (Lagerungsplagiocephalus, LP) ist die häufigste Kopfdeformität im Säuglingsalter. Die im Rahmen der ersten Kindervorsorgeuntersuchung (U1) erhobenen Daten wurden bezüglich der bekannten Risikofaktoren für die Entstehung eines LP ausgewertet. Im Rahmen der vorliegenden klinischen Pilotstudie wurde der Lagerungsplagiozephalus mitels der non-invasiven dreidimensionalen Sterophotogrammetrie untersucht und erstmals eine Normdatenbank von Säuglingen ohne Kopfdeformitäten erstellt. Die Therapie und Effektivität mittels modellierender individuell angefertigter Kopforthese, wurde evaluiert. Patienten und Methode: Untersucht wurden 20 Säuglinge mit einem Lagerungsplagiozephalus und schwerer Asymmetrie (Alter 6,0+0,97 Monate) und 20 Säuglinge ohne Kopfdeformität (Alter 6,4+0,3 Monate). Es erfolgte eine 3D-Weichteilanalyse des gesamten Kopfes. Zur Evaluation der Kopforthesentherapie wurden prä- und posttherapeutisch angefertigte sterophotogrammtriesche Aufnahmen dreidimensional ausgewertet. Ergebnisse: Anhand der im Rahmen der Erstuntersuchung erhobenen Daten zeigten sich bezüglich der Geburtslage und Art der Entbindung nur geringe Unterschiede. In der Patientengruppe kamen eine Beckenendlage und die Geburt durch Kaiserschnitt gehäuft vor. Die Anzahl der Spontangeburten zeigte sich in der Kontrollgruppe mit 70% größer als in der Patientengruppe mit 60%. Köpergröße, Körpergewicht und Kopfumfanges fielen in der Patientengruppe kleiner aus. Im Rahmen der vorliegenden Untersuchung wurden erstmalig 3D-Oberflächendaten von gesunden Säuglingsköpfen erhoben. Hierzu wurden die 360° Aufnahmen mittels lichtoptischen Verfahrens durchgeführt. Die reliable Auswertung der Säuglingsköpfe erfolgte in einem virtuellen Raum und diente zur Erstellung einer Normdatenbank. Bestehende Asymmetrien lassen sich mit diesem Verfahren quantifizieren. Die non-invasive 3D-Bildgebung kann somit zusätzlich zur klinischen Untersuchung und Sonographie als reliables Instrument in der Diagnostik und Verlaufsbeurteilung eingesetzt werden. Mittels der durchgeführten Aufnahmen konnten folgenden Parameter bei Säuglingen mit LP charakterisiert werden: - Die maximale Kopflänge zeigt sich bei vergrößertem Breiten/Längen-Index reduziert. Kompensatorisch erfolgt eine Vergrößerung der Vertexhöhe. - Die Ohrachse zeigt sich verschoben. - Die betroffenen Säuglinge weisen eine vergrößerte 30° Diagonalendifferenz auf und zeigen asymmetrische anteriore und posteriore Volumina des Neurokraniums. Schlussfolgerung: Die im Rahmen der Erstuntersuchung (U1) ermittelten Daten zeigten nur geringe Unterschiede zwischen der Patienten- und der Kontrollgruppe bezüglich Risikofaktoren für die Entstehung eines LP. Die Anzahl an Kaiserschnitten war innerhalb der Patientengruppe erhöht. Die im Rahmen der Pilotstudie untersuchte Anzahl Kinder ist allerdings zu gering um eine definitive Aussage treffen zu können. Die Therapie mittels individuell gefertigter Kopforthese hat eine Harmonisierung des Breiten/Längen-Index zur Folge. Eine posttherapeutische Verbesserung kann bezüglich der neurokraniellen Asymmetrie mit einer Reduktion der 30° Diagonalendifferenz und einer Angleichung der posterioren Volumina beobachtet werden. Die frühzeitige Korrektur, ab dem sechsten Lebensmonat, kann eine lagerungsbedingten Kopfdeformität frühzeitig korrigieren. Bezüglich der Bewertung des Langzeiterfolges der Helmtherapie sind noch weitere Studien notwendig. Insbesondere der longitundinale Aufbau einer Normdatenbank ist erforderlich, um physiologische Referenzdaten zu schaffen OBJECTIVE: Unilateral positional plagiocephaly is the most common deformity of the head in infants. As part of a prospective controlled clinical study, the pathomorphology of the positional plagiocephaly in early infancy was examined. The goal was to use noninvasive three-dimensional (3D) imaging to generate, for the first time ever, a standard database of infants without head deformities, to quantify the asymmetry of the positional plagiocephaly, and to evaluate the effectiveness of functional growth control using head orthesis. PATIENTS AND METHODS: In the present study, 3D soft-tissue data of the entire head were collected from a total of 40 infants: 20 with positional plagiocephaly (6.0 ± 0.97 months) and 20 infants without a head deformity (6.4 ± 0.3 months). Functional growth was controlled using a custom-made head orthesis. To evaluate the therapy, pre- and posttherapeutic scans were evaluated in three dimensions. RESULTS: The newbornscreening confirms the known risk factors of DP as male gender, number of deliveries and abnormal presentation. Compared with the control group, infants with positional plagiocephaly demonstrated a reduced maximum length of the head, an increased head height, a shift in the ear axis as well as asymmetric anterior and posterior volumes of the neurocranium in lateral comparisons. Therapy using head orthesis led to a significant improvement of the asymmetry, with a reduction of the diagonal difference and an adjustment of the posterior volumes. CONCLUSION: Conservative growth control of extrinsically deformed infant skulls represents an interdisciplinary medical expansion of the orthodontic therapeutic spectrum. To prevent potential effects of positional plagiocephaly on the viscerocranium, head orthesis therapy is advisable in infancy

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Dissertations / Theses on the topic 'Stereophotogrammetry'

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